Well those followers don't generate any traffic, their sole act of spamming is just following you. I'd just ignore it. And I think you just got +1 actual follower.
Well their sole act of spamming might be simply following me, but really it's a neat little trick.
1) Open a new Twitter account
2) Post some innocuous stuff, like poetry, or quotes
3) Post an advertising message
4) Add 10000 followers
5) Each of those goes back to your main page to see who you are and reads the spam message
6) $$$
I can see where this is going to get out of control very, very quickly.
Twitter imposed a 2000 follower limit because of that exact fact. You can never be following more than 2000+(#_of_followers). So maybe you can make $$ and not $$$...
