这应该是违法的！

只可私下交易。agent佣金不能以任何形式转给买房者。
也许该州的法不同，这个agent才敢这样公开做。
请看原文
Procuring Cause:

Seller is liable to pay a commission once he/she accepts an offer from a ready, willing and able buyer.

A broker can only pay another broker or a salesperson licensed to him or her. A salesperson can only accept a commission from his or her own broker