That's how to use Twitter as a personal marketing tool, but I personally block and mark as spam every person like that who follows me.

Here's the real secret to making Twitter Work For You If You're A Real Person: follow people you know and like. Look at who they talk to, follow those people if they seem decent. Talk to the people you follow as if they're your actual friends, because if they're not already eventually they probably will be.

You won't get four thousand followers. You might get new opportunities and contacts, and actual meaningful relationships with people. A direct application of this tactic, applied in the days before Twitter and Facebook, managed to get me a wife, so I think I'm doing better than the OP.