1. Building niche websites work better with adsense. As your ads targeting is much better. 2. When you’re building a new site don’t put adsense on it until it’s finished. 3. Always create channels for each ad. So that you know which ads aren't working. 4. Always blend your ads together with the content. Read on for the last one http://qala.blogspot.com/2008/10/tips-to-improve-your-google-adsense.html
I am agree with those tips. But the question is still about finding high pay advertiser on those niche... thanks for share..