I started http://folkd.com a social bookmarking service back in 2006. At the time Mashable called it a decent digg clone ;) I almost moved to the valley in the web2.0 phase to seek funding, but decided to stay in my home country to finish university. For 14 years now the site is providing a solid passive income from ads and freemium accounts as I was doing all of the coding and hosting myself. I moved on to other things for quite a while now, but the site is still going with good traffic and minimal effort. I think it could be much more, but I lack the motivation to rewrite the old PHP base. If someone wants to take over, shoot me an email to bk@folkd.com