After founding it in 1998, I sold gulli.com in February 2008, changing my life in a substantial way. With the help of more than 600k active members, gulli became one of the Top50 visited sites in Germany and Google Analytics counted more than 55.5 million pageviews from 9.8 million visits in January 2008. See this english and this german blogpost for more details. Ironic footnote: While the first buyer managed the community well, he also sold it on to Gamigo from Hamburg 5 years later, who then managed to run the community into the ground within weeks allowing me to buy domain and assets back 10 years after the exit...