Google Adwords

Tip #2 Correct Usage of Match Types

There are three match types in Google; broad, phrase, and exact. Check out Google's Adword's help documents for a discussion about how each one works.
Most people who are just starting out with Adwords make this mistake. They only bid on the broad match. That is, putting the keyword or phrase by itself with no quotes or brackets around it. In fact, Google has a built in suggestion to start out only using this match type. That is not always sound advice.
I recommend bidding on all three match types (this also effectively triples your keyword list). There is almost no way of knowing which match type will be the most effective for you. You need to try them and track them, then adjust accordingly.