Yes they are. To be honest they are one of my biggest sources of income. I wrote a small guide on how to approach them under “Start Here”.
Basically bookies like PointsBet, SPortsBet, BlueBet etc offer us refunds usually $50 – $100 if your horse comes 2nd, 3rd or 4th.
Best way to then approach them is to combine the offers, so for same race you back 3 different horses on the 3 bookies – increasing your chance of hitting a refund AND reducing your Betfair liability.