I know the solution, but it's illegal
hackertourism.com
hackertourism.com
Until you fix the problem of defaulting, finance will be an expensive proposition for unknown borrowers, too expensive for most non-asset purchases.
I don't have a solution for defaulting, but I do know that regulations make it near-impossible to run experiments that would lead to a solution.
The credit card company doesn't want the borrower to default, so they do a certain amount of checking before pre-approving the card to minimize that possibility across their customers (and charge a premium across the board to ensure they're covered even if some defaulters get through).
That's what I meant when I said "finance will be an expensive proposition for unknown borrowers"; they're not unknown (to the financer, i.e. the credit card company) if they have a credit card account.
The main idea is that it would have to be an option alongside Visa/MC/PayPal.
http://profy.com/2008/10/06/ebay-acquires-bill-me-later-to-m...
Abuse is another way companies like Uber increase "competition".
So I wonder what kind of abuse instant financing would entail among strangers.
Sounds just like a commission. If the problem is "marketplace founders are stumped when it comes to capturing any of that value for themselves", then the existing answers include commissions and referral fees. Setting up instant financing in order to have something to take a cut of may be a solution in search of a problem.
Perhaps I misunderstood something.
This could be disastrous and a recipe for bankruptcy if not managed properly. My biggest concern with this software is what type of person is likely to finance a $100 purchase from NewEgg, certainly not someone with good credit I would hope. I only use BillMeLater because it's interest free so, however minimal, I get 6 months of interest I wouldn't have normally gotten if I had paid immediately. This doesn't sound like what the OP wants to do.
That said, I'd never NOT purchase because of a lack of BillMeLater or similar services so it's not like adding this feature would give you access to new customers.
What the OP proposes is basically a credit card company, it's not really disruptive. Neither was BillMeLater.