There are lots of examples, if you look around - but I'm not sure how many of them were successful, as I haven't looked for data on that. John Dies at the End

There are lots of examples, if you look around - but I'm not sure how many of them were successful, as I haven't looked for data on that. John Dies at the End was originally published in a serial form online, though it has since been taken offline. It's been published, and is going into its ... second printing, I think, soon. From what I've heard, the fanbase is quite devoted (at one point, copies were sold for >$100 because of how hard it was to get them - the first printing was fairly small). Ichor Falls, a blog collecting short stories about the titular town, and the weird stuff going on around it, has a book - though that's recent enough that I don't know if it's successful. I also recall a zombie novel, which was published in serial form online before being published in physical form. Quite good, as I remember. Might have been called Empire - the plot synopsis fits what I remember, but the online serial version doesn't seem to be available any more. Once again, I don't know if it's what you would call successful. ... actually, what's the definition of successful? I would say that it's simply being published, after already been released online for free and building up a fanbase; however, I expect that most others would tie it to sales, or the amount of money the author gets from it.