Understanding eCPM, Fill Rate, and Viewability in Google AdX
As publishers work toward maximizing revenue with Google AdX, it's essential to understand the performance metrics that influence your earnings. Three of the most critical metrics in programmatic monetization are eCPM, fill rate, and viewability.
At PubShine, we help publishers not only get access to AdX but also understand how these metrics work and how to optimize them. In this blog, we'll break down each metric in simple terms, explain how they impact your revenue, and share tips on how to improve them.
What Is eCPM?
eCPM (effective Cost Per Mille) represents the estimated earnings per 1,000 ad impressions. It gives you a standardized way to compare ad performance across different channels and formats.
Formula:
Why it matters:
eCPM shows how valuable your inventory is to advertisers. A higher eCPM means advertisers are willing to pay more for your traffic, which directly boosts your revenue.
How to improve eCPM:
- Improve content quality and traffic sources
- Enable header bidding or open bidding to increase competition
- Use viewable and responsive ad units
- Run premium demand through trusted MCM partners
What Is Fill Rate?
Fill Rate refers to the percentage of ad requests that are successfully filled with an actual ad.
Formula:
Why it matters:
Low fill rate means lost revenue opportunities. If your ad units are not being filled, users see blank spaces or fallback ads, which negatively affects both user experience and earnings.
How to improve fill rate:
- Ensure your site is policy compliant and traffic is clean
- Diversify with multiple demand sources through PubShine's MCM network
- Optimize ad refresh rates and reduce latency
- Use adaptive ad sizes to maximize compatibility
What Is Viewability?
Viewability is the percentage of ads that are actually seen by users. According to Google, an ad is considered viewable if at least 50 percent of it is visible for at least one second (for display) or two seconds (for video).
Why it matters:
Advertisers pay more for viewable impressions. Google and most premium buyers prioritize inventory with high viewability rates, which directly impacts your eCPM and fill rate.
How to improve viewability:
- Place ads within the user's active screen area, especially above the fold
- Use lazy loading to delay ads until users are likely to view them
- Avoid stacking multiple ads too close together
- Optimize for mobile responsiveness and faster page loads
How These Metrics Work Together
Think of eCPM, fill rate, and viewability as connected levers. If your viewability is low, advertisers will bid less, reducing your eCPM. If your fill rate drops, it means impressions are being wasted. Together, these metrics define your site's monetization performance.
Improving just one metric can raise your overall revenue, but optimizing all three in harmony is where real growth happens.
How PubShine Helps You Optimize
At PubShine, we go beyond just providing AdX access. We actively monitor and optimize performance using these metrics. Our services include:
Advanced AdX Setup
Tailored for viewability and competition optimization
eCPM Monitoring
Ongoing monitoring and deal activation
Site Layout Audits
Optimization for higher fill and view rates
Real-time Dashboards
Expert optimization guidance and reporting
Whether you are new to programmatic or looking to scale, understanding and acting on these metrics will set you apart in a highly competitive ecosystem.
Want to Boost Your Site's Performance?
Let the team at PubShine help you unlock the full potential of your traffic. We partner with top MCMs and GCCPs to bring you premium demand, transparent reporting, and expert-level optimization.
📊 Apply now at PubShine.comStart your journey toward smarter monetization today.
