Previously, I discussed how comScore’s reach rankings are not keeping up with the emergence of RTB. Agencies use these rankings for planning and to help select media partners. Hence, it is critical for them to figure out how RTB potentially affects this measurement. Until everything is nicely squared away in measurement land, here are the five key questions that agencies should ask their media partners when deciding which ones are the most RTB-fluent.
1. Do you have your own bidder?
• Having a bidder gives the media partner control over scale (potential inventory and unique reach) and operational efficiencies. It is also an indicator of their level of technical investment and sophistication. With the expected growth of RTB and its applicability to all ad formats, owning a bidder is “table stakes” for any media partner that wants to offer scale.
2. Which exchange platforms are you bidding on?
• Publishers are increasingly testing/using multiple exchange platforms for monetization. To get the broadest inventory and reach coverage with the best economics, it is best to be bidding on multiple exchange platforms. Alternatively, access to a meta DSP such as AppNexus can provide RTB access to inventory on multiple exchanges, although at somewhat less attractive economics (for both network and end customer) relative to direct exchange integration.
3. What level of QPS (queries per second) do you have visibility to?
• QPS translates to “potential inventory.” So, higher QPS means more visibility and access to inventory and reach. Total exchange volume estimates range between 3B to 5B impressions per day in the US, which equates to 35K to 58K QPS. Exchanges enable “pre-targeting”, e.g. IAB ad-sizes, only certain sellers, domain whitelist, and other desirable constraints, which brings the total meaningful and desirable QPS range down.
4. What are your Response Rate/Win Rate Metrics?
• Response Rate is an indicator of how much exchange inventory is “interesting” – after pre- targeting – to a bidding media partner. Higher response rates indicate a richer demand pool and thus higher likelihood that the media partner is bringing some scale advantage to the table, i.e. the scale for fine-grained audience targeting.
• Win Rate (the % of bids that you submit on that you actually win) is an interesting metric, but only meaningful when combined with response rate. If the response rate is very high, then an ad network can achieve its inventory goal with a low win-rate. Conversely, a lower response rate would necessitate a higher win-rate to “earn” high inventory, reach, and overall ranking.
5. Bottomline: What is your incremental reach with RTB?
• Ultimately, it’s all about the relevant additional reach RTB fluency creates for a network beyond what is measured by the increasingly outdated comScore/Nielsen metrics. The critical variables in this regard are QPS, response/win rate, and the resultant “cookie reach.” Of course, cookies are not UUs but it’s how most networks do a basic approximation to UUs.
Let’s take a simple example to illustrate what we mean. Assume a modest 5000 QPS and a 50% response rate. This results in ~215 million impressions per day. Factoring cookies-to-UU adjustment and reach saturation over a typical month, we would estimate that this example partner has an overall potential reach of 145 million uniques per month.
For Brand.net, we had approximately 10K QPS and a 28% response rate in September. The resulting potential reach with RTB would have been 153MM uniques, increasing our reported reach of 92MM uniques by over 66%.
Of course, these numbers will vary depending on average campaign frequency, campaign breadth, and the contextual / audience focus of each partner. All further reinforcement that if “marketing is the new finance” and innovative marketers are already putting that dictum to practice, agencies and brands need to get familiar with the new math and metrics of RTB quickly.
This is yet another way RTB is altering the playing field for media providers, separating those with the technical investment and sophistication required to take full advantage on behalf of their customers. To date we have seen this trend primarily in the Direct Response world. Now it’s transforming Brand as well, so by this time next year we’ll see a very different landscape.

