Twitter Etiquette: Should You Follow Everyone That Follows You.
Jason Yormark
AUGUST 26, 2009
It seems to me that if you're not famous from the media, or already an established blogger, adding targetted people and hoping they follow you back is about the only way to grow your twitter audience if you have ideas you want to spread. I guess this fits into your spammer category, but this type of action is very prevalent.
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