I don't know anything about Twitter. I don't have a Twitter account or any intention of getting one.
So...this blog entry about the significance of Weiner following less than 200 people on Twitter and that one of them is the bimbo who was the target of his dic pic tweet was illustrative.
If you wanted to bait me into reading the link to get to the answer to the question, you were successful, my friend.
For the rest of you hard heads, I have read the article Trap linked. My interpretation is that Weiner enjoys the flattery of having young girls and porn stars follow him on twitter. I would speculate that they are a necessary "fantasy" for an aging man who apparently enjoys loving himself more than he does his wife.
An interesting note: I wondered how some boneheaded Congress-man could make such a mistake as to send a public message/penis-pic to the Seattle Slew. It's easy. According to the article Trap linked, on Twitter you can private message
those who follow you if you also follow
them. You can
public message anyone else you follow. The difference is the use of "@" and the use of "d".
I hope I got this right as it is important. Let's say I follow Ann Coulter's tweets. I can't send her a private message unless she follows me. But I can tweet anything on my Tweeter Account to be read publicly by anyone who follows me.