i'm very new with overture that's why i'm totally unaware of this (just explored it yesterday coz i got a task regarding our overture campaign. ). anyway, hope someone will give me a definitive answer: what is click index? use and purpose? is it necessary and what makes it REALLy necessary? how's it the same with google adword's ______ or msn adcenter's ________? sorry for the bunch of questions.
Click index compares your CTR with the CTR of your competitors' ads. If your click index is low you might want to consider changing your ad to see if you can improve it.