Little competition? There are a TON of companies in this market space, many of them well established. Just off the top of my head: Super Rewards, Offerpal, Gambit, Peanut Labs, etc...

And those companies are already driving down the margins. Most of the players in the market offer a 75% cut at minimum.

EDIT: Looking at their CPA page now I see that they're implementing Gambit. Guess they're in the same boat.