Ok I have been split testing, and I'm considering enabling the Search Network so that my listings are on sites such as AskJeeves, Lycos etc. What's your advice regarding split testings, as Google only take into account the CTR on Google - not the CTR on their search network partners. Would you just keep the Ad that's performed the best over Google + Search Network anyway, and hope this same ad was the best on Google only as well?
just roll over whatever works on google to their search partners. No need to worry about which ad works best on what ad network.