💰 Ad Placement Strategy

1. Standard IAB Units

We stick to industry-standard sizes to maximize demand source compatibility. Using standard sizes means every major ad network — Google AdSense, Media.net, Ezoic, Raptive — can fill your placements reliably.

• Leaderboard (728x90): Top of page, above nav (Desktop only). Very high viewability, but declining CTR as users develop banner blindness.
• Medium Rectangle (300x250): Sidebar or embedded in content. The single highest CPM unit in most markets — demand is universal.
• Large Rectangle (336x280): A bigger MREC that performs well embedded in article text after the first 2-3 paragraphs.
• Skyscraper (160x600): Right sidebar on desktop. Needs at least 600px of vertical content to look natural.
• Half Page (300x600): Premium sidebar unit with excellent fill rates and high eCPM on premium traffic.
• Mobile Banner (320x50): Sticky bottom or top on mobile. Low CPM but very high impression volume.
• Large Mobile Banner (320x100): Twice the height of the standard mobile banner, commands a premium over 320x50.

For a harm-reduction educational site like Psilobase, contextual relevance matters. Many ad networks will serve wellness, gardening, or psychology-adjacent ads which fit naturally. Avoid accepting ad categories that are antithetical to the site's ethos (e.g., recreational drug dealers, irresponsible supplement claims).

2. Placement Map

Where ads appear is as important as which sizes you use. The goal is maximum viewability without disrupting the reading flow.

High-Performing Positions

• Above the fold (ATF): Ads visible on page load without scrolling have 2-3× higher viewability scores. The leaderboard and first sidebar MREC are ATF placements.
• Mid-article (anchor): An MREC or large rectangle placed after the third paragraph captures readers who are engaged. This is often the best-performing position by revenue.
• End-of-article: Readers who finish an article are highly engaged. A placement here captures that audience before they navigate away.
• Sticky sidebar: An MREC that follows the user as they scroll generates very high viewability scores (>70%), increasing CPM.

Positions to Avoid

• Between heading and first paragraph: Interrupts content immediately and increases bounce rate.
• Multiple consecutive ads: Never place two ad units back-to-back. Always have at least one content paragraph between ads.
• Floating overlays on mobile: These violate Google's Better Ads Standards and can trigger manual penalty actions in Search Console.

3. UX Rules and Technical Standards

• No Layout Shift (CLS): Always reserve space for ads before they load. Google PageSpeed and Core Web Vitals penalise cumulative layout shift. If an ad doesn't fill, collapse the container gracefully — never leave a gaping blank space.
• Labeling: Always label ads clearly ("Advertisement" or "Sponsored"). This is required by the FTC in the US, ASA in the UK, and is good practice everywhere. Users who know it's an ad are less likely to feel deceived and more likely to trust your editorial content.
• No Pop-ups or Interstitials: Avoid any ad format that blocks content, especially on mobile. Google penalises intrusive interstitials in mobile search rankings.
• Lazy loading: Load ad scripts after the main content is interactive. Use async and defer attributes, and consider loading ad tags only after the user scrolls past the fold.
• Ad density limit: Google's policies cap ads at roughly 30% of total page content. Exceeding this risks account suspension.

/* Reserving Space for Ads — prevents CLS */
.ad-container {
  min-height: 250px;      /* Match the ad unit height */
  background: #f8f9fa;    /* Neutral placeholder */
  margin: 20px 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Label above every ad unit */
.ad-container::before {
  content: "Advertisement";
  display: block;
  font-size: 11px;
  color: #999;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-align: center;
  margin-bottom: 8px;
}

/* Graceful collapse if ad doesn't fill */
.ad-container:empty {
  display: none;
}

4. Privacy and Consent

Most ad networks that serve personalised advertising require a GDPR-compliant consent mechanism for users in the European Economic Area. For Psilobase:

• Display a cookie consent banner before loading any ad scripts that set third-party cookies.
• If the user declines personalised ads, switch to contextual ad serving (no tracking cookies).
• Implement a Consent Management Platform (CMP) that integrates with your ad network's SDK.
• Store consent state in a first-party cookie and re-check on each page load.

Google AdSense and AdX both have built-in CMP tools. Ezoic has "Humix" consent management. Always verify that your specific network's consent requirements are met before going live.

5. Performance Optimisation

Ads are among the heaviest resources on most web pages. Poor ad performance directly harms Core Web Vitals scores and organic search rankings.

• Lazy load below-the-fold ads: Use Intersection Observer to only initialise ad slots when they enter the viewport.
• Limit third-party scripts: Each ad network adds scripts, pixels, and trackers. Consolidate to 1-2 networks maximum.
• Monitor LCP impact: If your largest contentful paint element is near an ad slot, that ad's loading time will directly delay your LCP score.
• Test with and without ads: Run PageSpeed Insights in both states to quantify the performance cost of your ad setup.

// Lazy load ads with Intersection Observer
const adObserver = new IntersectionObserver((entries) => {
  entries.forEach(entry => {
    if (entry.isIntersecting) {
      // Load ad now
      googletag.display(entry.target.id);
      adObserver.unobserve(entry.target);
    }
  });
}, { rootMargin: '200px' }); // Load 200px before viewport

document.querySelectorAll('.ad-container').forEach(el => {
  adObserver.observe(el);
});

6. Revenue Optimisation Tips

Once your ad setup is technically sound, the next priority is maximising revenue per thousand pageviews (RPM).

• A/B test placement: Move ads 1 paragraph earlier or later and compare eCPM over 2-week periods.
• Header bidding: Networks like Prebid.js allow multiple demand sources to compete for each impression simultaneously, lifting prices.
• Seasonality: Ad CPMs spike in Q4 (October–December). Maximise your placements during this period.
• Geographic targeting: Tier-1 countries (US, UK, CA, AU) pay 3-5× the CPM of Tier-3 traffic. Understand your audience's geography to set realistic RPM expectations.
• Viewability score: Advertisers pay premiums for viewability above 70%. Use sticky placements and above-the-fold positioning to improve this metric.