It's a game of skill much in the same way as poker. Experienced players will beat inexperienced players over the long-run. There are certain elements of randomness/luck (as with poker, sometimes you just get bad cards) - but DFS proponents would argue that identifying under-valued players and predicting performance to be a skill.

Surprisingly, the NBA and MLB have an official DFS partnership - as do individual teams in both the NFL and NHL. Some individual players also have "endorsed" certain sites.

Full list of DFS partnerships: http://www.legalsportsreport.com/dfs-sponsorship-tracker/