I personally would never be so desperate as to give this company a chunk of revenue in exchange for matching me with a business guy. If you truly do not know anyone with whom you want to start a company, move. Really. Moving costs less than giving these jokers 9.9% of every sale.
The processing fee we charge is irrelevant to whether we are a good place to find co-founders. Actually, you could use FairSoftware, find people, use our Software Bill of Rights to start your business, and never pay us a cent.
You only pay the processing fee if you use our payment backend. If your project consists of two people, then by all means, work out a deal by yourselves. But if you are trying to build something with a larger community of contributors, and having transparent sharing brings value and trust to your contributors, then you'll find out that our fees are reasonable.
And as someone pointed out, we don't actually charge much at all for ourselves, we mostly pass other people's fees (PayPal) to you so we don't lose money. We are working on lowering the total fees, and it has to do with ACH and treating non-US contributors differently than US contributors, but we will eventually, in order to save money for you.
There are scenarios where we are way cheaper than any alternative. If you are a couple of students with very little money to invest, we give you a legal structure, some amount of protection and privacy from your end users, for literally no money down.