I judge a boating internet site's impact on how many boats are advertised for sale, as of today OSO has 826, which is down form the 1,000 boats that were listed a few years ago, and now SOS has risen to 272 boat listings, SOS on the way up, gradually, on OSO has dropped. This may be too simplistic of an analysis, but the numbers are the numbers. My $..02 thought for the day. I like the both sites, but seem to here more often for the threads, and more so at OSO for the classifieds, but that habit is changing.
As Geronimo36 (Frank said), I like them both, and my drive is to go boating, if possible.