Google AdSense testing new text ad formats

In a Webmaster World thread posted yesterday, an AdSense publisher observed that some of his text ads had been displaying in different formats.

A subsequent post in the thread from an AdSense representative gave the standard “Google is constantly testing” response, indicating that tests like that are closely monitored and only shown to a small percentage of impressions.

The original poster also included descriptions of the variations he was seeing. I’ve mocked up some ads using those descriptions to give you an idea of what you might see if you were searching for an “iPad 2”:

AdSense text ad variations

It will be interesting to see whether there are any long term changes to text ads based on this testing. Personally, I kind of like Variation 1 because it puts the title tag and the URL close enough together that they could be visually processed together – I can quickly glance at the ad, and get an idea of the content from the title and the reliability/familiarity/brand affinity/etc. from the URL, without having the description in the way.

Eye tracking research has shown that centered text is harder to read than left-aligned text, because there’s extra mental processing required to determine where the next line begins. I don’t think the centered ads will perform as well (although they might initially, just from a “novelty” perspective).

Variation 4 would be my least favourite. Eye tracking research has also shown that searchers, for the most part, skim down the left side of search results – by going to two lines, that means a searcher would see the first couple of words of the title and then some (probably out of context) text from the middle of the description. I’m also the least convinced about this one in terms of what the publisher was reporting, since it’s wider than the standard 300px width of an AdSense box. However, the publisher also commented that he’d seen changes to the font style, so perhaps that would make it fit.

What do you think – which variation will perform best?