We recently started receiving "Writer's Digest" magazine in the 7th - 12th-grade school library where I work.
          I eagerly started flipping through it, finding all sorts of interesting things.  An article on "Flash Fiction" (just a hip new term for short-short fiction), information about various literary markets, and some profiles of new first-time authors.
          I noticed that they used the same questions for each of the 3 or 4 new authors, asking who they are, what they've written, and what their "Platform" is.  I was puzzled by "Platform," and stopped to read each of those answers.
          Apparently "Platform" refers to your public following, or how you attain your public following.  It's all about built-in fans/readers, which is something publishers totally look for.  So these newly-published writers were all talking about their blogs mostly, and shit like Facebook, Twitter, and MySpace, I guess.  However they regularly connect with readers, and drum up NEW readers.
          So "Platform" in the publishing industry doesn't seem to refer to what you're trying to say and/or do, your viewpoint/convictions (as it does in politics), but rather just HOW and WHERE you say it.  As long as you're saying it a lot.
          For example: Kim Kardashian's "Platform" would be her reality show(s), Twitter, and probably Facebook, MySpace and every other form of media.  A publisher would probably look at Kim Kardashian and say, "She has a GREAT platform, a huge built-in audience, YES, let's DEFINITELY publish her book."
          (Does she already have a book?  I know that retarded bitch from the Hills does, and several other brainless celebutantes who have other people write shit for them.) 
          Sigh.  What was I saying?  Oh, yeah-- "Platforms." 
          So I guess I better work at blogging more, and trying to pay attention to what OTHER people are blogging or posting on Facebook or whatever.  Talk about a necessary evil.  We just saw a report on TV last night that something like 7 out of 10 Tweets go un...  What do you call that?  Un-Tweetbacked?  Un-responded-to?  Anyway, the point was that nobody cares about anybody ELSE'S Tweets or blog posts or Facebook posts, we tend to just care about what WE'RE saying.  And if we ARE responding to other people's chattering, it's only in the hopes that they'll respond to OURS.
          This is no surprise to anyone, but I guess we have to keep on doing it, especially us creative types who need to appease the literary and art publishers.