AsSense Relevancy Evolution

Does AdSense "learn" which ads (ad topics) perform the best for your site.

[dflayfield]

I have noticed that, over the last 7 monhts, my ad relevancy has improved dramatically. I have gone to great lengths to improve relevancy by optimizing my pages but I wonder....
Does AdSense learn over time which types of ads work best on your pages. I would think it would be well within the capability of the AdSense engineers to design algos that "learn" which ads perform better than others. Over time, AdSense could learn which ad topics should be served based on each ads CTR.

Has anyone else noticed relevancy increasing as the ads age on your pages? And how much of this can be attributed to your optimization efforts?

Dave

[loanuniverse]

I don't think this was introduced when it first came out. I think we are seeing the result of refining over time, and this refining might even have to do with someone at Google making a decision to classify your site into a category.