The punch card graph for the Open Source engine behind Lichess that he wrote is... impressive! https://github.com/ornicar/lila/graphs/punch-card
For more info, see http://lichess.org/blog/U4skkUQAAEAAhIGz/why-is-lichess-free
Also note that we suck at marketing, but it doesn't matter, since we don't do it at all.