I just found out about this one yesterday. I wished I knew about this sooner as I might have won $30 from winning at least one match with $10 above odds (single).
Yes, $ 10 is the prize for the 10th placer. Whoever accumulates the most points will be the winner of the top prize. There is a tally for every day. And the winners are based on accumulated and aggregate points over a week. There is one player who scored 11+ K points yesterday if you look at the record in the forum thread. This is probably a high bettor ($ 10 or above) he bets then he still makes Parlay bets, max 45 points for Parlay bets of a match.