Scrolling AdSense Ads and Questions on CPC

Every AdSense publisher should have heard or read about those new AdSense scrolling ads by now. It was a nice improvement aimed at visitors interacting with ads. Question is, do readers really interact with ads?

The introduction of scrolling ads mean that a wider selection of advertisers will be available to the visitors by just clicking on the scroll arrows. With the limitations of the ad space, scrolling ads make sense just like those LED marquees you see everywhere.

I think this development has got to do more about CPC rather than CTR. Those who are not yet familiar with how Cost-Per-Click (CPC) is determined by AdSense, here are some ideas you might want to know.

• CPC is directly determined by the bid amounts made by AdWords advertisers. The more bidders, the higher the CPC as competition pushes the keyword prices up. One quick way to check whether a bid for a keyword is high is by searching for it on Google and looking at the number of ads displayed on the right side of the search results.
• Just like AdSense for Search, the placement of ads in AdSense for Content is also arranged by highest bidder. That means that the first ads displayed on your page will most likely have the highest CPC. If you have 3 ad placements, a click on an ad at the 3rd box will more likely cost less than the one on the 2nd and the 1st. In essence, the more ad spots you have, the more likely you’d get a lower CPC on average.

In theory, having scrolling ads will most likely affect the CPC as the succeeding ads in the scroll will cost less to the advertisers (due to bid priority).

The contradicting statistical probability now is between the chances that “a visitor clicks on a default ad which costs more” or “a visitor more likely to click on a scrolled ad that costs less”. Would be interesting to see field tests on ad CTR due to scrolling ads and compare them with the eCPM.