"Tipping a deal" is an artificial constraint. The only thing it does in the model is incentivize customers 1 ~ 10 to bring in customers 11 ~ 200+. You can use any manner of means to prevent deals from failing, from shill-tipping to just out-and-out lying about that artificial constraint actually existing. (The ability to guarantee 200+ customers to the merchant is nice, but you can finesse this by good selection of starting deals or subrosa agreements with the merchant where you either deliver 200 customers or the deal is free and you'll compensate them.)