Yes, it's a two-sided market like estate agents (realtors) and used car salespeople. But without enough turnover to do statistical satisfaction management like Uber. And the dating company problem that satisfied customers don't come back.

Most of them are just trying to churn you through the sales process quickly; some are outright scammers (if you've not had to blacklist a recruitment firm you've probably not done much hiring); and a very few are absolutely gold who will matchmake better than automated systems. Those people deserve positive word-of-mouth.