[alapshah]

Seems like it might be a pretty complicated thing to add... No other marketplaces that I know of have their own processing capabilities... Third party aggregation (taking payments on behalf of someone else) has many quite-complicated regulatory issues.

[patio11]

In addition to the regulatory issues, you're asking to get a bunch of customer support complaints over $25 transactions where your maximum upside is measured in pennies. And many of those complaints are going to sound like:

Buyer: "The seller never shipped the itemz!"

Seller: "I did, too! With no tracking number, because I'm new at this, like most of your users!"

Buyer: "I fell off the Internet for two weeks because I didn't pay my phone bill but I'm back now and hopping mad because the booties that just got delivered have WOOL instead of COTTON in them!"

Seller: "It says right in the description NATURAL FIBERS!"

Buyer: "There is nothing natural about FACTORY FARMS!"

Accountant: "Total cost to read this email thread so far: $14 and counting. Value of this transaction to us: $0.57."

Buyer + Seller: "YOU GREEDY CORPORATE BASTARDS."

[gabaix]

Yes. Also you need big sales volumes to justify the investment in time / money.