Paul Edmondson, YieldBuild’s CEO, was quoted in a recent Wired post on the state of online ad prices. Digging into our data on contextual ad networks (which I had shared on contextual ad rpc trends on this blog at the end of July), we noticed a slow drift downwards in Q3, and a noticeable resurgence in RPC values before the tumult of the financial sector meltdown.

Paul shared his thoughts on fluctuations in RPC payouts to publishers, explaining that changes tend to be gradual, with the recent turbulence rather unusual.

Full article at Wired.

Yoni Baciu, one of YieldBuild’s engineers, has overlaid imprints of 20,000 ads randomly selected from the Web’s top 100,000 Websites (by traffic) on one blank slate. The result is YieldBuild Lab’s Heat Map which renders the most popularly-selected positions on a Web page with a brighter red glow.

What does the Heat Map tell us?

First, header position ads, and sidebar ads (particularly on the right side), are popular, and ad density also decreases as you go down the page. The darkest portions of the Heat Map are to lower-left.

This is not to say that this a protocol for placing ads if you want to maximize performance. Generally, ads should be within a users’ line of sight, close to navigation elements, and embedded in read content. But site-specific recommendations are usually the result of careful testing (or implementation of YieldBuild, which finds the best-performing regions for each page algorithmically).

Interesting, Google’s own recommendations for AdSense publishers suggest heavier weighting towards the top of content (although not necessarily the header) and also favoring the left more than the right.

If Google’s recommendations for AdSense publishers prove to be generally true for publishers using other networks as well, then that darker-red zone to the middle-left probably presents some opportunity to increase revenue, although without YieldBuild or testing, there’s no way for a publisher to know.

In February, TechCrunch published a post on how changes to the way AdSense determines a valid click led to lower CTRs (click-through rates) for publishers. This was not really a surprise; as I wrote back then, this was primarily a bid to ensure click quality on behalf of advertisers. And not only AdSense–there were rumblings on publisher boards earlier this year about Yahoo Publisher Network, a rival contextual ad network, showing the same dropping CTR problem.

But CTR is only part of the revenue equation. RPC (revenue per click) determines how much the average click is worth to a publisher. Interestingly, the data we’ve assembled shows that RPCs are rising among the most popular contextual ad networks. Looking at data drawn from a publisher base comprising over 4 billion monthly page views shows a steady climb—about 60% over a seven-month period—in RPC among publishers using the most popular contextual advertising networks in use today.

Why? There are two possible explanations. First, the contextual ad networks are giving a greater share of advertiser revenue to publishers, to counterbalance fears that tightening CTRs will lead to losses of revenue and prompt searches for alternate ad networks. Second, we might be seeing the effect of rising competition among online advertisers, as advertising spending continues to move online. Contextual advertising gives advertisers the option to pay only when a user expresses interest in an ad (by clicking), so it’s a natural pick for advertisers with performance goals in mind.

We have no idea if the rise in RPC makes up for—or exceeds—any losses through lower CTRs, and, regardless, the situation will be different for any particular publisher and their specific content and traffic patterns. Again, these are aggregate trends from a pool of publishers, and each publisher might see data that deviates from this trend. Each ad network calculates RPC in a different way for each publisher. But the trend for this sample of publishers is clear: when visitors click, expect more, not less.