Years ago, if you wanted to contact an author, you waited until they went on tour. Or you sent them a letter or more recently you sent an email. These things were likely all filtered through an agent so that the author didn’t have to deal with it all.
Now with Twitter accounts, Facebook author pages, Tumblr, and blogs (and I’m sure several other forms of social media) readers have the chance to directly interact with their favorite authors. Some authors are heavily involved with their followers. Maureen Johnson, Cassandra Clare, and Melissa Marr all frequently respond and retweet questions from followers on Twitter, which is really cool.
As a writer, this is both something I look forward to and dread. It would give my readers a direct line to me so that they can tell me how much they love my books, so that they can worship the ground I walk on.
It also means that they can tell me every place I screwed up. It means they can point out where they think I could have done it better.
And you can’t please everybody.