I just noticed that the CEO of PayByChip has introduced himself in the restricted user thread so he can answer the questions posed here.
I don't see that PayByChip being only one person is a bad thing, every company, no matter how large, started somewhere with just one person with an idea. Consider Apple, for instance, Steve Wozniak and Steve Jobs started it in Jobs's garage. Or Microsoft who was started by Bill Gates and a friend, their only product was a BASIC interpreter for the Mits Altair 8800.
For Amazon Prime members, Amazon won't allow current Prime member to use their Prime benefits, like two day shipping, on the marketplace, they will however be offering marketplace users the ability to get Prime two day shipping on marketplace orders for $50 per year. It's not available yet, but it is coming. Currently the only thing I'm using Prime for on Amazon is the two day shipping, so, for me, that would be a 50% savings over Amazon's price.
Just in case PayByChip doesn't work out, though I think they are off to a great start, I will be maintaining my Amazon account, I will however be deleting my debit card from it and canceling my Prime membership.