Google Paid & Ctr Rankings, CTR and Cost for Rank Help Options

[Superbob]

Hello again everyone,

I am fairly new to this whole advertising on google and overture. Overture I have been able to pick up really easy however google I am struggling on. I pretty much have two questions. From what I understand is that google unlike overture isn't just based on how much I PPC. However I believe it is based on a CTR rating and how much you pay. So if company A has a 25% CTR and company B has a 10% CTR both pay $1.00 a click Company A would be listed ahead of company B. Well would adding the same words such as google, "google", and [google], would that impact the CTR if currently just using [google]. But if you fill your list up with a bunch of phrases that nobody clicks would google penlize you for this and make you pay more to be in the same position you have always been? Currently I pay less for my spot on the advertising I am assuming due to my high CTR rate. However I want to add more key words to potentially increase business however I don't want to injury my CTR rating so that I have to pay more for my current positon on my primary words. So how exactly would I accomplish this by building a new campaign so it doesn't injury my CTR in my other campaign. Can someone please shed some light on this for me thanks.