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Ad Slot Best Practices

Optimize your ad slot configuration for revenue and user experience.

Naming conventions​

[page]_[position]_[number]

Examples​

Slot nameMeaning
homepage_header_1First header slot on homepage
article_sidebar_topTop sidebar on articles
article_incontent_1First in-content placement
category_sidebar_1Sidebar on category pages
mobile_sticky_footerMobile sticky footer

Do's and Don'ts​

DoDon't
Use lowercaseHomepage_Header
Use underscoresarticle-sidebar
Be descriptivead1, slot_a
Include positionJust sidebar
Keep consistentMix conventions

Size selection​

Do​

  • Use IAB standard sizes — Highest demand
  • Include 2-3 sizes per slot — More competition
  • Match sizes to design — Natural fit

Don't​

  • Use obscure sizes — Low demand
  • Add too many sizes (5+) — Unpredictable
  • Use sizes that don't fit — Bad UX
PositionSizes
Header728x90 + 970x250
Sidebar300x250 + 300x600
In-content300x250 + 336x280
Mobile320x50 + 300x250

Placement guidelines​

Above the fold​

PracticeWhy
Prioritize viewabilityFirst impression matters
Use high-impact sizes970x250, 728x90
Limit to 1-2 slotsDon't overwhelm
Disable lazy loadingNeeds to load immediately

Below the fold​

PracticeWhy
Enable lazy loadingImproves page speed
Use standard sizes300x250 works everywhere
Consider refreshUsers spend time here
Stack in sidebarNatural scroll behavior

In-content​

PracticeWhy
Place after 2-3 paragraphsNatural reading break
Use content-width sizes300x250, 336x280
Space evenlyEvery 4-6 paragraphs
Enable lazy loadingAfter first placement

Mobile optimization​

Key practices​

  • Test on real devices — Emulators aren't perfect
  • Use mobile-specific sizes — 320x50, 320x100, 300x250
  • Check touch targets — Ads shouldn't block navigation
  • Verify viewport fit — No horizontal scroll

Mobile-specific settings​

SettingRecommendation
Sticky footer320x50, careful with UX
In-content300x250 works well
InterstitialsUse sparingly
Refresh60+ second intervals

Performance optimization​

Lazy loading​

Slot typeLazy load?
Above-fold headerNo
First sidebarNo
Second+ sidebarYes
In-content (first)Maybe
In-content (2+)Yes
Below-foldYes

Refresh settings​

SettingRecommendation
Interval45-60 seconds
Maximum refreshes3-5
Require viewabilityAlways
Sticky adsLonger intervals (90s+)

Learn more: Ad Refresh →

Common mistakes​

MistakeProblemSolution
Too many adsHurts UX and CWVLimit to 4-6 per page
Wrong sizesLow fill, poor revenueUse standard sizes
No lazy loadingSlow pagesEnable for below-fold
Vague namesHard to manageUse naming convention
Ignoring mobileLost revenueTest and optimize
Never adjustingStale performanceReview quarterly

Testing changes​

Before significant changes:

  1. Use experiments — A/B test variations
  2. Monitor for a week — Short tests aren't reliable
  3. Compare key metrics — Revenue, CPM, fill rate, CWV
  4. Check user metrics — Bounce rate, time on page
  5. Roll back if negative — Don't force bad changes

Learn more: Experiments →

Maintenance schedule​

Weekly​

  • Check for slots with zero impressions
  • Review any error alerts

Monthly​

  • Review slot performance (CPM, fill rate)
  • Identify underperformers
  • Check floor price effectiveness
  • Use bulk updates for floor adjustments across slots

Quarterly​

  • Remove unused slots
  • Update sizes based on performance
  • Review against industry changes
  • Audit naming consistency

Optimization checklist​

For each ad slot, verify:

  • Name follows convention
  • 2-4 appropriate sizes
  • Lazy loading set correctly
  • Floor price configured
  • Added to correct layouts
  • Mobile experience tested
  • CLS impact minimized

Next steps​