I built and run http://theclunkerjunker.com. It started as an affiliate site I started on a whim one night (Or a few hours, more accurately). Within a year it was pulling in $30k/month with almost no expenses. Eventually the affiliate program fell apart and I completely re-wrote it and turned it into a legit service. I don't quite make $30k a month anymore, and it's noticeably more work now, but it's still profitable and I can work at my own pace.
