If you can make the campaign profitable by discovering many little niche keywords would you
a) Be happy and stop there
b) Keep running the high volume/high priced keywords balancing the loss from the other keywords until they become profitable through lowering CPC slowly?
Of course option b is a lot more work...but more fun as well :)
We ran each one for a week after each other and the 4th we ran all 3 at the same time.
To our surprise the 2 highly targeted campaigns did not perform as well as the cheaper general one, but the 4th week when we had all 3 running did the best by far.
All 3 were running at between 600-1000% ROI
I know a week for each campaign is not a long time to test, but we cannot afford to lose too much while doing it.
We are already looking into more niche cheaper terms to expand on.
If i were you, I wouldn't just stop, find more niche key phrases. i am sure there will be more out there.
briggidere