Spot on. Job boards need to fail more than they successfully place people, so that employers and job seekers keep trying. Similarly it's not in the dating sites

Spot on. Job boards need to fail more than they successfully place people, so that employers and job seekers keep trying. Similarly it's not in the dating sites best interest if everybody finds their soul mate. They need losers. Losers with money to spend. Same is true with your personal trainer in the gym, she/he only wants you to keep training safely and continuously. In all these examples the incentives with the primary actors and the middlemen doesn't align.