5 Essential Metrics to Improve Header Bidding Performance

Header bidding is a technique where the publisher simultaneously offers the same ad impression to multiple ad exchanges. Once the highest bid is selected, it is sent to the ad server and the chosen creative is displayed. The idea is that by allowing multiple demand sources to bid on the same inventory simultaneously, publishers can increase their yield and generate more revenue.

Today, over 70% of publishers use header bidding to maximise yield, but tracking performance and optimising results can be complex and time-consuming. From bid rate and win rate to timeout percentages, several key metrics directly impact your monetisation success.

In this guide, we’ll walk you through the five crucial header bidding metrics you need to monitor. By understanding what these KPIs mean and how to act on them, you can optimise your header bidding setup for better performance and more revenue, without the guesswork.

5 Key Metrics to Follow in Header Bidding

• Win rate - Win rate shows how often a bidder wins the auction compared to how often they submit a bid. It’s a direct reflection of how competitive a bidder is within your setup. A consistently low win rate might mean the bidder isn't offering competitive bids, and could be adding unnecessary weight to your page.
• Bid rate - Bid rate tells you how often a bidder responds to an ad request. A low bid rate can flag issues such as misconfiguration, technical errors, or low demand from that partner.  Tracking bid rate helps identify underperforming demand sources and ensures strong competition in the wrapper, which directly affects your fill rate.
• Fill rates - Fill rate is the number of impressions divided by the number of ad unit requests sent. It gives you the percentage of ad displays that have been sold. A low fill rate might mean there's insufficient demand, overly aggressive floor prices, or buyer-side filtering due to issues like poor viewability, brand safety concerns, or technical problems.
• Auction eCPM - This metric gives the revenue generated per 1,000 header bidding auctions, including the unfilled ones. It’s especially useful when comparing performance across sites, geos, or inventory segments. Think of it as a holistic view of how well your setup is monetising each opportunity.
• Timed out bids% - This metric tracks the percentage of bids that arrive after the timeout threshold. Unlike simple bid latency metrics, timed-out bids (%) tells you how many bids were too late to matter, which can significantly impact auction competition and revenue. Persistent timeouts may suggest the need to adjust timeouts or reconsider slow-performing partners.

Tracking these five metrics isn’t just about looking at numbers—it’s about knowing which bidders are actually driving revenue, which ones are slowing down your page, and where you can make changes that lead to faster load times, higher fill rates, and stronger auction outcomes.

No time to dig through endless reports? Relevant Yield’s Header Bidding Analytics (HB Analytics) gives you a real-time overview of bidder performance, so you can instantly spot things like underperforming bidders, excessive timeouts, or missed revenue due to low win rates.  And with Relevant AI, our built-in assistant, you don’t need to be a data expert. It helps you analyse performance across sites and geos, surfaces unusual patterns (like a sudden drop in bid rate or fill rate), and suggests optimisation actions—like adjusting floor prices or removing laggy bidders.

In short: better decisions, faster actions, more revenue—without the guesswork.

HB Analytics Simplifies Optimisation

Relevant Yield’s Header Bidding Analytics empowers publishers and sales houses to take full control of their header bidding performance. It offers real-time insights into bidder behaviour across major platforms, including Prebid, Amazon TAM, and Google Ad Manager (GAM)—so you can monitor and optimise every aspect of your programmatic setup.

With HB Analytics, you can easily drill down into SSP, vendor, and placement-level metrics, making it simple to:

• Identify top-performing demand partners
• Detect technical issues like bid timeouts or drops in response rates
• Take timely action to protect and grow your programmatic revenue