Betnomi sponsored a few competitions and free raffles like this one or this one. In the german local board there were also two or three free raffles where you could also win a free bet. At the moment I don't think there is a free raffle where you can win a free bet, but hopefully there will be some again soon. 
I think you are right about that, and I joined Betnomi Champions League pool so that must be rewards for yellow caps in previous rounds.After long break in Champions League because of world cup, we should finally come back for playoff matches in two weeks.
Congratulations again to all the winners!