Exactly this. A great example is apps like Coffee Meets Bagel which sometimes tout themselves as the "solution" but then have a separate section of "select" can

Exactly this. A great example is apps like Coffee Meets Bagel which sometimes tout themselves as the "solution" but then have a separate section of "select" candidates that you have to pay to talk to. So basically if you have a desirable profile (in this case it's basically if you're hot because that's the primary part of a profile), they monetize you without your knowledge or permission and charge the other side to initiate conversation.