Greetings, Ed, and welcome to my blog!
The relevance of the adverts seems to be reasonably good right out of the box, but then I’ve been using Google’s Sitemap for some time on the theory that that will help keep their indexes of my site current. That said, I did notice a pretty significant improvement in relevance even within the first few days- now AdSense is showing ads for cold remedies on my main page in response to my “I’ve got a cold” post 🙂
I like your advice regarding setting up an alternate ad- maybe something in my left or right nav. But I think I’ll let things settle for a bit and become more familiar with how the program works before I get too crazy about optimizing.
By the way- I hope you don’t mind, but I edited your post to correct the link to your website (http://www.technologyevangelist.com/). YOu missed an “e” in there originally.