Callisti has been optimising adword account ad variations for time lapse photography suppliers, Lobster Pictures, and is noticing an almost immediate improvement in CTR (Click through rate) and a reduction in CPC (Cost per click).
The best way to do this is to target the ad to the most relevant content, which usually means pages on the website aside from the homepage. By using the Ad structure you can match the search string closer to the Ad title and related the keywords in the ad copy to the landing page.
This is logical as the keyword relevance in the ad should match the keywords of the landing page. Otherwise you’re not targeting your Ads very accurately!