Hey Guys, So Google now has Broad Match Modifiers (BMM)! So, if you add a "+" in front of any keyword, that word or a word closely relative to becomes a required element in the user search string. Here's the article: http://www.rimmkaufman.com/rkgblog/2010/07/14/broad-match-modifiers-are-here/
I wouldn't touch that or broad match with a 10 foot pole ever. It's too unfocused and will end up with un-targeted traffic. Great for adwords, horrible for performance marketers.
You are right that the traffic is not that targeted but.. using broad match can be great when you are testing a new campaign and you are looking to get more traffic with more keywords after the campaign is running for a while you can browse the search queries and add more relevent keywords and negative keywords.
well, i guess, that's better for testing purposes, not for a target campaign, because it can have some unexpected results in your goals, maybe for an introductory campaign, or to research marketing behaviour