Could not put this better myself:
"Think about it: Here's a forum where you write for a sizable, high-quality audience about anything that interests you. Here's a forum where you can eternally debate other people obsessed with ideas. Here's a forum where you can instantly pose as a public intellectual - and try to "fake it till you make it." Here's a forum that actually penalizes atrocious academic writing!"
Yup. http://econlog.econlib.org/archives/2011/02/why_do_so_many.html