This is the article that mentions the letters http://finance.yahoo.com/news/impressed-delighted-warren-buf...

Very interesting model where everyone (apparently) can set a hotline to give advice and make some money. Some folks you can reach are: Eric Ries http://clarity.fm/#/ericries , Dan Martell http://clarity.fm/#/danmartell

Seems like github is doing it right by following the motto of "investing in humans [...] to build the best company".

Keep up the good work!