Twitter is growing like a weed, up 1000% so there are lots of people to meet. Getting to know people and giving them a way to find out who you are and what you are about is important and twitter is of great value for this.
Following the conversation in your market area is more important. I believe having a deep understanding of your market through seeing what people are saying and doing is critical. Every market exists as a constant flux of changing opportunities.
Being able to track your competition is also very important. By following conversations at places like http://search.twitter.com much can be seen.
Recently in a niche market I am active in I saw there was a slight variation of one of my main keywords more commonly used than the one I had originally chosen. That was valuable to know and by using the more commonly used variation I saw a slight traffic increase for blog posts using the more popular term.
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