Twitter “auto followers”

Given the nature of Twitter, I don’t understand those who just automatically follow everyone who shows up on the Twitter home page. I just blocked about 5 “followers” who were each following a couple of thousand people. Some were following as many as 80k people! Clearly they’re not actually “following” any of them, just automatically adding everyone who posts, hoping to GET as many followers as possible. “TwitterMosaic”? If I wanted to see everything posted by everyone on twitter, I’d just look at the twitter home page, not follow a specific user, who just reposts everything everyone says.
Then there was the guy who’s every tweet was “Let me help you make your life better! Read my web site! makemoneyfast.com” and variations thereof. Yeah, I need twitter spam about as much as I need email spam.
On the other hand, having finally gotten up and started my e-day, one of the first emails I read told me a lovely red-head and good friend had started following me on Twitter. 🙂