Just discovered a new blog I had not read before, that has a pretty good long article about PPC testing and tracking.
"Testing and tracking is probably the best thing you can do for your PPC campaigns. Through testing and tracking, you can gain a very important edge over all your competitors: the ability to make more money from the same amount of traffic. Once you gain this edge, many additional opportunities become available to you. You can afford to pay more for traffic, giving you higher placements and more traffic from PPC engines, and you get chances to profit from other traffic sources."
Source: DerekBeau.com
How And Why To “Test & Track” Your Pay-Per-Click Marketing Campaigns