how did I manage to get millions of pics taken at con, and not have a single one posted here? T^T
As far as I can tell from almost ten years of cosplay, the general rule of thumb is, for every twenty random people who stop you for a photo, expect to find one picture of yourself actually uploaded online. If fewer than twenty people stopped you, it's more or less up to chance.
(The odds improve significantly if one of the random people is a big-name photographer with a website - especially if you get their card.)