Splitting Traffic, not Hairs

SearchEngineWatch: Split Traffic, Raise Conversion Rates, Repeat, Multiply

This is a very good article by Eric Enge over at SE Watch. It's very well laid out, and all the terms are defined for those of us that are still novices. As most PPC experts out there will attest, it is very important to segment your traffic, and find out what about your site is successful.