Because of the current "minimum bid" requirements, it is imperative that you only bid on search terms that are specifically focused on your product or service. The more specific the keyword, the better it is likely to convert into a sale. Conversely, for most people, it is usually no longer worthwhile sponsoring general keywords; they are worth less than the minimum bid. Do the research to figure out what specific search terms apply to you (read my search engine optimization article for tips on how to do this; in particular, use the WordTracker service).Rule #3: If you are bidding on a keyword that isn't the prime focus of your site, my advice is, at first, simply bid enough to get on the bottom of the list. Later, once you know how much those clickthroughs are worth, you can raise your bid to get more clickthroughs, but note that often, the higher up on the page your link appears, the less valuable it becomes (because of the filter effect).