Conversion Rate Optimization skill 08 of 13

Popups and On-Site Messaging SKILL.md

The Popups and On-Site Messaging skill makes Claude, Codex or another AI agent plan popups, banners, slide-ins and prompts that help rather than annoy. It chooses formats and triggers, caps frequency and suppresses offers for customers, matches offers to page types, avoids mobile interstitials that can hurt search, handles consent and accessibility and measures net effect against holdouts.

popups-onsite-messaging/SKILL.md, version 1.0.0, 1,524 words.

Popups, banners, slide-ins and in-page prompts can grow email lists, recover abandoning visitors and guide people to the right offer. They can also annoy visitors, hide content, slow pages and, on mobile, harm search visibility: Google has long warned that intrusive interstitials that block content on mobile can hurt how pages perform in search. [Confirmed, Google page experience guidance] The difference lies in relevance, timing, design and restraint.

This skill plans and improves on-site messages: when to show them, to whom, with what offer, in what format, how often and how to measure their real effect, including on bounce, conversion and search.

Operating principles

  1. Relevance beats volume. Show messages that match the page, the visitor and their stage.
  2. Timing matters. Exit intent, scroll depth and engagement triggers outperform immediate popups.
  3. Never block the main content on arrival, especially on mobile.
  4. Make closing easy. A visible close button, no tricks, and respect for dismissals.
  5. Measure net effect. Captured emails mean little if overall conversion or revenue falls.

Formats

FormatBest forWatch out for
Centre modalHigh-value offers on desktop exit intentIntrusive on mobile
Slide-in (corner)Content offers, chat promptsCan be missed
Top or bottom barShipping thresholds, announcementsTakes vertical space on mobile
Inline promptsContent upgrades inside articlesLower visibility
Full-screen takeoverRarely appropriateSearch and user experience risk
Exit-intent modal (desktop)Last-chance offers, lead magnetsOveruse trains visitors to ignore

Triggers and targeting

TriggerUse
Exit intent (desktop)Offers to visitors about to leave
Scroll depth (for example 50 to 70%)Content upgrades for engaged readers
Time on pageHelp prompts after meaningful time
Page typeDifferent offers on blog, product, pricing and cart pages
Traffic sourceMatch offers to campaign or referral context
Visit countAvoid showing the same offer every visit
Cart valueFree shipping threshold reminders

When to use, and when not to

Use it to grow email or SMS lists, promote relevant offers, reduce abandonment, announce changes and guide visitors to help.

Don't use it to fix confusing pages (landing-page-optimisation) or as a substitute for clear checkout costs (checkout-optimisation).

Inputs to ask for, in one message

  1. Current popups and banners with triggers, targeting and results.
  2. Goals: list growth, sales, lead capture, help.
  3. Offers available (discounts, guides, tools, free shipping thresholds).
  4. Traffic by device, source and page type.
  5. Consent requirements for email and SMS capture.
  6. Tool used (for example Klaviyo, OptinMonster, Privy, custom).

Raw SKILL.md file

.md

This is the exact file agents read, including the credit header and licence notice. Save it as popups-onsite-messaging/SKILL.md.

---
name: popups-onsite-messaging
description: "Plan on-site popups, banners, slide-ins and prompts that help rather than annoy: formats, exit-intent, scroll and page-type triggers, frequency caps and suppression, offers matched to pages, mobile interstitial risk for search, clear consent, accessible design and net effect measured against holdouts on conversion and revenue. Use whenever someone asks about popups, exit-intent offers, email capture forms, slide-ins, announcement bars, free shipping bars, on-site messaging or whether popups hurt conversion or SEO."
license: CC-BY-4.0
metadata:
  author: Afeez Adebayo
  author_url: https://afeezadebayo.com
  author_linkedin: https://www.linkedin.com/in/afeez-adebayo/
  author_x: https://x.com/za_icon
  source: https://afeezadebayo.com/skills-md/marketing/conversion-rate-optimization/popups-onsite-messaging/
  category: marketing
  subcategory: conversion-rate-optimization
  version: "1.0.0"
  created: "2026-10-10"
  updated: "2026-10-10"
---

# Popups and On-Site Messaging

Popups, banners, slide-ins and in-page prompts can grow email lists, recover abandoning visitors and guide people to the right offer. They can also annoy visitors, hide content, slow pages and, on mobile, harm search visibility: Google has long warned that intrusive interstitials that block content on mobile can hurt how pages perform in search. [Confirmed, Google page experience guidance] The difference lies in relevance, timing, design and restraint.

This skill plans and improves on-site messages: when to show them, to whom, with what offer, in what format, how often and how to measure their real effect, including on bounce, conversion and search.

## Operating principles
1. **Relevance beats volume.** Show messages that match the page, the visitor and their stage.
2. **Timing matters.** Exit intent, scroll depth and engagement triggers outperform immediate popups.
3. **Never block the main content on arrival, especially on mobile.**
4. **Make closing easy.** A visible close button, no tricks, and respect for dismissals.
5. **Measure net effect.** Captured emails mean little if overall conversion or revenue falls.

## Formats
| Format | Best for | Watch out for |
|---|---|---|
| Centre modal | High-value offers on desktop exit intent | Intrusive on mobile |
| Slide-in (corner) | Content offers, chat prompts | Can be missed |
| Top or bottom bar | Shipping thresholds, announcements | Takes vertical space on mobile |
| Inline prompts | Content upgrades inside articles | Lower visibility |
| Full-screen takeover | Rarely appropriate | Search and user experience risk |
| Exit-intent modal (desktop) | Last-chance offers, lead magnets | Overuse trains visitors to ignore |

## Triggers and targeting
| Trigger | Use |
|---|---|
| Exit intent (desktop) | Offers to visitors about to leave |
| Scroll depth (for example 50 to 70%) | Content upgrades for engaged readers |
| Time on page | Help prompts after meaningful time |
| Page type | Different offers on blog, product, pricing and cart pages |
| Traffic source | Match offers to campaign or referral context |
| Visit count | Avoid showing the same offer every visit |
| Cart value | Free shipping threshold reminders |

## When to use, and when not to
Use it to grow email or SMS lists, promote relevant offers, reduce abandonment, announce changes and guide visitors to help.

Don't use it to fix confusing pages (`landing-page-optimisation`) or as a substitute for clear checkout costs (`checkout-optimisation`).

## Inputs to ask for, in one message
1. Current popups and banners with triggers, targeting and results.
2. Goals: list growth, sales, lead capture, help.
3. Offers available (discounts, guides, tools, free shipping thresholds).
4. Traffic by device, source and page type.
5. Consent requirements for email and SMS capture.
6. Tool used (for example Klaviyo, OptinMonster, Privy, custom).

## Workflow

### Step 1. Inventory
List every on-site message, where it shows, when and to whom, with views, conversions and dismissals.

### Step 2. Check harm
Compare bounce, conversion and revenue per visitor for sessions that saw messages versus those that did not, and check mobile intrusiveness.

### Step 3. Match offers to pages
Blog readers get content upgrades; product pages get buying help or shipping thresholds; cart pages get reassurance, not distractions.

### Step 4. Set triggers and frequency
Exit intent or engagement-based triggers; cap frequency; suppress for customers and recent subscribers.

### Step 5. Design well
Clear headline, one action, visible close, mobile-friendly size, accessible focus handling.

### Step 6. Handle consent
Clear opt-in wording, separate SMS consent, link to privacy notice.

### Step 7. Test with holdouts
Measure net effect on conversion and revenue against a group that sees no message.

## Copy patterns
| Goal | Example |
|---|---|
| Email capture with discount | "Get 10% off your first order" (only if the business can afford it) |
| Content upgrade | "Download the full checklist as a PDF" |
| Shipping threshold | "You're £12 away from free delivery" |
| Help prompt | "Choosing a plan? Answer two questions for a recommendation" |
| Exit intent on pricing | "Questions about plans? Talk to us or see the FAQ" |

## Measuring net effect
| Metric | Why |
|---|---|
| Message conversion rate | Direct performance |
| Overall conversion and revenue per visitor (vs holdout) | Net impact |
| Bounce and engagement | Annoyance signals |
| Email or SMS quality (later purchases, unsubscribes) | Value of captured contacts |
| Mobile search performance on affected pages | Interstitial risk |

## Message rules by page type
| Page type | Show | Avoid |
|---|---|---|
| Blog and guides | Content upgrades after scroll | Discount popups on arrival |
| Product pages | Delivery threshold, size help, stock alerts | Generic newsletter prompts |
| Pricing page | Plan recommendation help, FAQ link | Discounts that undercut list prices |
| Cart and checkout | Reassurance (returns, security) | Anything that pulls attention away from paying |
| Account pages | Product updates, help | Acquisition offers |

## Accessibility checklist
- Focus moves into the message when it opens and returns when it closes.
- The close button is labelled and reachable by keyboard.
- Escape closes the message.
- Text contrast meets accessibility guidelines.
- Screen readers announce the message and its purpose.

## Frequency and suppression rules
- Show an offer at most once per visit and pause it for several days after a dismissal.
- Suppress acquisition offers for subscribers and customers.
- Suppress all marketing messages during checkout.
- Cap the number of messages any visitor can see in a session.

## Holdout design
Keep a random share of visitors (for example 10%) who never see marketing messages. Compare conversion rate, revenue per visitor and bounce between the groups each month to confirm messages add value overall.

## Edge cases and judgement calls
| Situation | What to do |
|---|---|
| Discount popups train customers to wait | Test non-discount offers; limit to first-time visitors |
| Many messages from different teams | One owner and a priority order |
| Legal notices (cookies, age checks) | Keep them compliant and minimal; they are not marketing popups |
| Low traffic | Avoid many variations; focus on one relevant offer |
| Returning customers | Suppress acquisition offers |

## Handoffs to related skills
- Page clarity: `landing-page-optimisation`
- Copy: `conversion-copywriting`
- Mobile: `mobile-conversion`
- Test planning: `cro-test-planning`
- Email and SMS follow-up: the CRM and Lifecycle skills
- Interstitials and search: the Technical SEO `core-web-vitals` skill

## Worked example
A fashion retailer showed a full-screen 15% discount popup on every page after three seconds, on all devices. List growth was high but revenue per visitor had fallen, and returning customers complained. The new plan removed the immediate popup on mobile, showed a slide-in after 50% scroll for first-time visitors, used exit intent on desktop, added a free-delivery threshold bar on product and cart pages and suppressed offers for customers. A holdout test showed revenue per visitor rose while list growth stayed healthy.

## Output format
```
# On-site messaging plan: <site>, <date>
## Inventory and current results
## Harm check (bounce, conversion, revenue vs holdout)
## Offers by page type
## Triggers, targeting and frequency
## Design and consent rules
## Test plan and metrics
```

## Common mistakes
- Immediate full-screen popups on mobile.
- The same discount for everyone, every visit.
- Hidden or tiny close buttons.
- Measuring sign-ups but not net revenue.
- Many teams launching overlapping messages.

## Questions to ask before you add a message
- What does this visitor need on this page right now?
- Will the message help or interrupt?
- How will we measure net effect?

## Self-check before you answer
- Are messages relevant to page and visitor?
- Are triggers engagement-based with frequency caps?
- Is mobile content left unblocked on arrival?
- Is net effect measured against a holdout?

## Further reading
- Google Search Central on intrusive interstitials: https://developers.google.com/search/docs/appearance/avoid-intrusive-interstitials
- Nielsen Norman Group on modal dialogs: https://www.nngroup.com/articles/modal-nonmodal-dialog/

---
Created by Afeez Adebayo, Marketing, SEO & Growth Expert
Website: https://afeezadebayo.com
LinkedIn: https://www.linkedin.com/in/afeez-adebayo/
X: https://x.com/za_icon
Source: https://afeezadebayo.com/skills-md/marketing/conversion-rate-optimization/popups-onsite-messaging/

Licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). You may copy, share and adapt this skill, including for commercial use, as long as you credit Afeez Adebayo and link to the source URL above. Keep this notice in any copy or adapted version.

Workflow

Step 1. Inventory

List every on-site message, where it shows, when and to whom, with views, conversions and dismissals.

Step 2. Check harm

Compare bounce, conversion and revenue per visitor for sessions that saw messages versus those that did not, and check mobile intrusiveness.

Step 3. Match offers to pages

Blog readers get content upgrades; product pages get buying help or shipping thresholds; cart pages get reassurance, not distractions.

Step 4. Set triggers and frequency

Exit intent or engagement-based triggers; cap frequency; suppress for customers and recent subscribers.

Step 5. Design well

Clear headline, one action, visible close, mobile-friendly size, accessible focus handling.

Clear opt-in wording, separate SMS consent, link to privacy notice.

Step 7. Test with holdouts

Measure net effect on conversion and revenue against a group that sees no message.

Copy patterns

GoalExample
Email capture with discount"Get 10% off your first order" (only if the business can afford it)
Content upgrade"Download the full checklist as a PDF"
Shipping threshold"You're £12 away from free delivery"
Help prompt"Choosing a plan? Answer two questions for a recommendation"
Exit intent on pricing"Questions about plans? Talk to us or see the FAQ"

Measuring net effect

MetricWhy
Message conversion rateDirect performance
Overall conversion and revenue per visitor (vs holdout)Net impact
Bounce and engagementAnnoyance signals
Email or SMS quality (later purchases, unsubscribes)Value of captured contacts
Mobile search performance on affected pagesInterstitial risk

Message rules by page type

Page typeShowAvoid
Blog and guidesContent upgrades after scrollDiscount popups on arrival
Product pagesDelivery threshold, size help, stock alertsGeneric newsletter prompts
Pricing pagePlan recommendation help, FAQ linkDiscounts that undercut list prices
Cart and checkoutReassurance (returns, security)Anything that pulls attention away from paying
Account pagesProduct updates, helpAcquisition offers

Accessibility checklist

  • Focus moves into the message when it opens and returns when it closes.
  • The close button is labelled and reachable by keyboard.
  • Escape closes the message.
  • Text contrast meets accessibility guidelines.
  • Screen readers announce the message and its purpose.

Frequency and suppression rules

  • Show an offer at most once per visit and pause it for several days after a dismissal.
  • Suppress acquisition offers for subscribers and customers.
  • Suppress all marketing messages during checkout.
  • Cap the number of messages any visitor can see in a session.

Holdout design

Keep a random share of visitors (for example 10%) who never see marketing messages. Compare conversion rate, revenue per visitor and bounce between the groups each month to confirm messages add value overall.

Edge cases and judgement calls

SituationWhat to do
Discount popups train customers to waitTest non-discount offers; limit to first-time visitors
Many messages from different teamsOne owner and a priority order
Legal notices (cookies, age checks)Keep them compliant and minimal; they are not marketing popups
Low trafficAvoid many variations; focus on one relevant offer
Returning customersSuppress acquisition offers
  • Page clarity: landing-page-optimisation
  • Copy: conversion-copywriting
  • Mobile: mobile-conversion
  • Test planning: cro-test-planning
  • Email and SMS follow-up: the CRM and Lifecycle skills
  • Interstitials and search: the Technical SEO core-web-vitals skill

Worked example

A fashion retailer showed a full-screen 15% discount popup on every page after three seconds, on all devices. List growth was high but revenue per visitor had fallen, and returning customers complained. The new plan removed the immediate popup on mobile, showed a slide-in after 50% scroll for first-time visitors, used exit intent on desktop, added a free-delivery threshold bar on product and cart pages and suppressed offers for customers. A holdout test showed revenue per visitor rose while list growth stayed healthy.

Output format

# On-site messaging plan: <site>, <date>
## Inventory and current results
## Harm check (bounce, conversion, revenue vs holdout)
## Offers by page type
## Triggers, targeting and frequency
## Design and consent rules
## Test plan and metrics

Common mistakes

  • Immediate full-screen popups on mobile.
  • The same discount for everyone, every visit.
  • Hidden or tiny close buttons.
  • Measuring sign-ups but not net revenue.
  • Many teams launching overlapping messages.

Questions to ask before you add a message

  • What does this visitor need on this page right now?
  • Will the message help or interrupt?
  • How will we measure net effect?

Self-check before you answer

  • Are messages relevant to page and visitor?
  • Are triggers engagement-based with frequency caps?
  • Is mobile content left unblocked on arrival?
  • Is net effect measured against a holdout?

Further reading

When to use this skill, and when not to

Use it to grow email or SMS lists, promote relevant offers, reduce abandonment, announce changes and guide visitors to help.

On-site messages can grow lists and recover visitors, or they can annoy people, hide content and hurt mobile search performance. Google warns that intrusive interstitials blocking content on mobile can affect how pages perform. Relevance, timing, design and restraint make the difference.

Don’t use it to fix confusing pages (use Landing Pages) or to hide checkout costs (use Checkout).

Example prompts

  • “Are our popups hurting revenue?”
  • “Plan exit-intent offers for desktop.”
  • “Which popups should we show on blog pages?”
  • “Set frequency caps and suppression rules.”
  • “Do mobile popups hurt SEO?”

Example output

The skill returns a fixed structure. A shortened example for an imaginary site:

# On-site messaging plan: example fashion retailer, 11 October 2026

Before: full-screen 15% popup after 3 seconds, all pages, all devices
After: no immediate mobile popup; slide-in at 50% scroll for first-time visitors; desktop exit intent; free-delivery bar on product and cart pages; offers suppressed for customers
Measure: revenue per visitor vs a 10% holdout

Messages are judged on net revenue against a holdout group, not on sign-ups alone, because a popup can grow a list while lowering sales.

What the agent needs from you

The skill asks for current messages with triggers and results, goals, available offers, traffic by device, source and page type, consent requirements and the tool in use.

How this skill hands off to related skills

On-site messaging connects to the set: page clarity in Landing Pages, words from Copy, phones in Mobile, scheduling in Test Planning, follow-up with the CRM and Lifecycle skills and interstitials with the Technical SEO Core Web Vitals skill.

How to run Popups and On-Site Messaging step by step

  1. Install the skill as popups-onsite-messaging/SKILL.md.
  2. Inventory every message and its results.
  3. Check harm against a holdout.
  4. Match offers to page types.
  5. Set triggers, caps and suppression.
  6. Design, handle consent and test.

Situations this skill handles

On-site messaging goes wrong in familiar ways. The skill handles these situations:

SituationWhat the skill does
Discounts train customers to waitNon-discount offers
Many teams adding messagesOne owner and priority order
Legal noticesKept compliant and minimal
Low trafficOne relevant offer
Returning customersAcquisition offers suppressed
Mobile interstitialsDelayed or removed on arrival

What makes this skill different

Most popup advice optimises sign-up rates. This skill optimises net revenue: it matches messages to pages and visitors, controls timing and frequency, protects mobile experience and search, and proves value against a holdout.

Accessibility and consent are part of the design, not an afterthought.

Practical tips from real projects

  • Relevance beats volume.
  • Timing matters.
  • Never block content on arrival.
  • Measure net effect.

A worked example: a fashion retailer showed a full-screen 15% discount popup on every page after three seconds, on all devices. List growth was high, but revenue per visitor had fallen and returning customers complained. The new plan removed the immediate popup on mobile, showed a slide-in after 50% scroll for first-time visitors, used exit intent on desktop, added a free-delivery threshold bar on product and cart pages and suppressed offers for customers. A holdout test showed revenue per visitor rose while list growth stayed healthy.

Formats suit different jobs. Centre modals work for high-value offers on desktop exit intent but are intrusive on mobile. Corner slide-ins suit content offers and chat prompts. Top or bottom bars suit delivery thresholds and announcements but take space on small screens. Inline prompts suit content upgrades inside articles. Full-screen takeovers are rarely appropriate because of the user experience and search risks.

Triggers decide relevance: exit intent on desktop, scroll depth around half to two thirds of a page for engaged readers, time on page for help prompts, page type for different offers on blog, product, pricing and cart pages, traffic source to match campaign context, visit count to avoid repetition and cart value for delivery threshold reminders.

Rules by page type keep messages helpful. Blog and guide pages get content upgrades after scrolling; product pages get delivery thresholds, sizing help or stock alerts; the pricing page gets plan help and FAQ links rather than discounts that undercut list prices; cart and checkout pages get reassurance about returns and security and nothing that pulls attention away from paying; account pages get product updates and help.

Frequency rules show an offer at most once per visit, pause it for several days after a dismissal, suppress acquisition offers for subscribers and customers, suppress marketing messages during checkout and cap the number of messages per session.

Accessibility requires focus to move into the message and back on close, a labelled close button reachable by keyboard, escape to close, sufficient contrast and screen reader announcements.

A holdout keeps around 10% of visitors free of marketing messages, so conversion, revenue per visitor and bounce can be compared every month.

Copy follows the goal. An email capture offer might promise a first-order discount only where the economics allow it; a content upgrade offers the full checklist as a PDF; a delivery bar tells shoppers how far they are from free delivery; a help prompt offers a plan recommendation in two questions; and an exit message on the pricing page points to the FAQ or a conversation with the team.

Consent is handled clearly: opt-in wording that says what people will receive, separate consent for SMS, a link to the privacy notice and unticked boxes where the law requires them. Captured contacts are judged by their later purchases and unsubscribe rates, not only by how many signed up.

One person owns the messaging calendar so different teams do not stack overlapping offers on the same visitors.

Mobile search performance on affected pages is monitored after every change to interstitials.

Frequently asked questions

They can when they interrupt; relevant, well-timed messages measured against a holdout often help.

Google warns that intrusive interstitials blocking content on mobile can affect performance in search.

Exit intent on desktop, scroll depth and engagement, rather than immediate popups on arrival.

At most once per visit, paused after dismissal and suppressed for subscribers and customers.

Sometimes, but test non-discount offers too, since discounts can train customers to wait.

Compare conversion and revenue per visitor with a holdout group that sees no messages.

Changelog

  • 1.0.0, 10 October 2026: first release.

Use, adapt and share this skill under CC BY 4.0: credit Afeez Adebayo and link to this page.