I've seen this model a lot lately (not a criticism, just a fact). The internet has certainly created plenty of opportunity to bring buyers and sellers of a particular product together and create an efficient marketplace. What you have, though, is a classic chicken-and-egg problem. You need buyers to attract sellers, and you need the sellers to attract buyers.

Without knowing the actual market / product, it's difficult to give much advice, but one thing that I've seen help in this scenario is to take your market, and further slice it into niches, and focus on one niche to begin with. This gives you a couple of advantages:

1. It allows you to get hyper-focused on who your customer is, making introductions / referrals easier. This is counter-intuitive, but the more narrow your focus, the more likely you are to get other people to understand what you are looking for and send prospects your way.

2. It allows you to get maximum bang-for-buck in advertising and marketing, because your audience is more narrow and easy to identify. You can also target specialized trade shows or other, similar marketplaces where that audience can be reached (again, I don't know any detail about your business, so I'm generalizing).

3. It allows you to refine the MVP with a very narrow audience before opening it up to a wider group after it's been proven. You may find that changes are needed in order to widen your audience / customer base, but that's OK - you've proven that the model works and is worth investing in further.

I would be glad to discuss your model in detail and give you some more specific examples of what I've seen work if you are interested in scheduling a call.