Well, maybe I am being a bit too lofty. It can be about keeping up with your favorite celebrity. It can be about keeping in touch with distant friends and relatives. It can be used in any way you want.
But there are some people who use it only for self-serving purposes. Their twitterfeed is a non-stop litany of self-promotion. It's like listening to a needy, unsure of themself four year old clamoring for attention. "Mommy! Look what I can do!" There are others, worse still, who think that they can use it as a blunt tool solely for making money. How the hell they would accomplish that is beyond me. I get a few of these as followers from time to time. Very often, I block them. To me, Twitter is a social tool; being associated with their ilk makes it a bit creepy and dirty. Yuck.
Sarah Palin falls into the first category. How do I know? Look at the image from her Twitter profile. She doesn't follow a single person. Not even Glenn Beck, Michelle Malkin... Hell, not even P. Diddy and it seems like the whole twitterverse follows him (2.3 million followers)! Basically, where Sarah Palin is concerned, all communication is one-way: I speak, you listen. She doesn't want to hear from you and doesn't care what you have to say as long as you buy her book and you think that she's a "real American." Please don't ask her about her views on foreign policy (it's in the book) and when you address her make sure that you address her as Governor Palin and please... no photos (unless you want to purchase an "autographed" one at one of her book signings - only $30.)