If you'd like to make some spare change or big money with Google AdSense or Shopping.com or other pay-per-click advertising opportunities, then check out these blog posts:
Erik at ProductWiki.com provides an interesting look at how Google AdSense and Shopping.com ads pay off for his consumer electronics review blog. Check out his post at http://blog.productwiki.com. Pay attention to what he has to say. Then read the following post:
Eric Guiguere, author of Make Easy Money with Google and AdSense, provides some inside advice on how to optimize your Google AdSense listings. Read his blog here: http://www.memwg.com/blog.
Then read his book. A great read if you want to make passive income from your websites (besides selling your books). I use Google AdSense on most of my web sites except for my main BookMarket.com website. In the next several months, though, I plan to redesign that site as well to include Google ads. It just makes sense to use AdSense to increase your subsidiary income.
You can order Eric's book by clicking on the cover image above.