I keep seeing people complain about liquidity at Fairlay but every time I check it out myself, I can see some pretty big orders there, for sure more than 1 BTC for even the lines I bet,,, I do not think there are that many whales who go for exchanges!

Keep promoting them and they will grow, just like OP says, Betfair took a long time to become popular and that is with fiat which almost everyone could use.