Question: So what ads attract the most attention?
Answer: It depends on what you're going for...
For users to click on ad, it's important for that ad to stand out. Take a look at these two Adsense examples (one text, one image)
Assuming the viewer was indifferent to the content of the ads above, it's not hard to see why an image ads handily beat text ads. Here's what Google had to say about image vs. text ads
While we can’t make any guarantees about the earnings potential of image or text ads, we believe that image ads will prove to be a high-performing option for publishers looking to monetize their pages. In fact, we show image ads when they have a higher value to you than the corresponding set of text ads that might otherwise run in the same slot.
Now that we've established that image ads generally lead to more clicks, lets talk about which ad size will lead to the most revenue. As always, the publisher should never have ads that are so large--or small--that they distract from the content. Though the decision to choose tasteful ad sizes is yours, here's what Google had to say about their best performing sizes.
The sizes we've found to be the most effective are the 336x280 Large Rectangle, the 300x250 Medium Rectangle, and the 160x600 Wide Skyscraper.
There you have it. If you want to make the most money, go with an 336x280, 300x250, or 160x600 image ad.
Please comment with your experiences below. Next time I'll do an in-depth analysis of Google Adsense vs. Chitika