You have to maintain a .05% CTR (click through rate) for Google to continue displaying your Ads. The more keywords the better. The more *targeted* keywords - the better
Broad keywords tend to give you a high # of Impressions, and sometimes a high CTR (not always) -but dont generally result in SALES. The more targeted keywords are your best bet - and plenty of them.
For example:
business web hosting instead of
web hosting - and using "free" as a negative keyword.
Stefani - you'll want to do the split-testing of Ads within the Ad Group itself. The best way to do this is to turn off Ad Optimization, as suggested above, and write two Ads. When it becomes obvious which one performs better (results in a higher CTR), you'll replace the other Ad with a new one to test against this good one. And you can keep doing this (it's called "Beat the Controller") until you figure out *exactly* what it is that the targeted market responds best to.