Exact and phrase matching have their place but I believe there is a case for only using broad matching.
Similar points have been made in the past. You might want to read this post:
[webmasterworld.com...]
Now, we had a lot of intelligent conjecture among ourselves, but never did get an answer to the most important questions from AWA.
The only "fair" way it could work would be if an [exact] or "phrase" match that 'matched' your broad match was taken into consideration and was given a "point" for having turned up in your campaign. No reason to think it works that way though.
Additional points:
a) I have noticed a "liberalization" of even newly created broad matches recently. They're more likely to match variants earlier on of late.
b) Unless it's a "hot" phrase, don't enter all 3 types of matching initially. Hold at least one back in case the match type in use gets disabled. You can thus extend the life of a keyword that is profitable enough for you but doesn't meet AdWords standards.
patient2all