Because it changes an awful lot. The keyword might be $2.50 CPC when it is exact but will change to $16.00 when it is broad...and also some keywords are not even there when it is changed.
I always use "exact" for all my stats with the search per month, CPC and competition. Should I be using the broad option as well? Coz I dont understand what the purpose of the broad option is and how it effects all the data so much?
I am really just trying to find good CPC for my keywords that I want to use for adsense...that's why I use "exact" but maybe I am missing something here?
Can somebody please explain what all this means?