From today’s New York Times.

‘An author’s platform has long been something publishers look at — does she have a radio show, for example, or a regular guest spot on TV? But as local news outlets and book coverage have dwindled, the avenues for book publicity have shrunk, making an author’s ability to help get the word out more crucial. And when an author speaks to her followers about a book she wrote, she is talking to people who are at least a little bit interested in what she has to share.

“It’s become more and more important as the years went on,” said Marc Resnick, executive editor at St. Martin’s Press. “We learned some hard lessons along the way, which is that a tweet or a post is not necessarily going to sell any books, if it’s not the right person with the right book and the right followers at the right time.”’