I think you need something you can charge for immediately, like eduardordm said. I understand that you have a marketplace of sorts where two parties must meet prior to a transaction but it's very unclear what it is you're doing.

The fact that you have an MVP, you're already talking to prospects and there are barriers to entry that you're having difficulty with makes me ask, why the secrecy? People would have trouble catching up to you at this point, and even if they did, they would face the same problems you're currently having.

This conversation would probably be much better and more helpful if people knew what you're doing. Then their answers wouldn't be, "find something to charge for", they would probably be, "You could probably do X for the side of the marketplace you have currently until the other side shows up. Charge them for that to keep you going for now."