I've been saying this all along, but Mark Jackson on SEW just wrote about how pages that are organically optimized for SEO make great landing pages that can improve your quality score. That's not news. But I thought these comments were pretty interesting:

Google is asking that you have a targeted page for every keyword that you would like to advertise against. They're saying that if the keywords aren't in the title tag, content, and if the page isn't specific to the keywords that you would like to advertise against, there's a good chance that the page won't show up in the top Google AdWords listings, even if you're willing to pay or bid the highest amount for a listing there.

(emphasis is mine)
How many advertisers are actually building a separate page for each keyword they want to advertise for?

And apparently Google is serious about your ad's CTR.

The AdWords blog has reported that they often apply a "disabling rule" that inhibits ads with very low CTRs for a given query from being shown.

And Jackson speculates that Google may be looking at CTR in the organic SERPs as well when deciding on placement. Seems quite likely to me. A "disabling rule"?

Yep, we were just discussing yesterday the move of a site to #1 in SERPs... and exactly the activity required to keep that position as it is being measured for quality. I would suggest that if there are any barriers to providing a nice, long, "sticky" session, it is best to remove them when your site enters the first page on Google for your target keywords.

...oh, and contrary to current plans, you might not want to make any structural changes while your SERPs are still "dancing."