> holding and tracking other people's money has a cost.
When you have as many users as PayPal does, in aggregate those non-zero balances are a mountain of money to play with. It's not a cost, it's opportunity for profit.
Presumably it costs more to keep the money and process login attempts. Since logging in is enough to keep the account at zero fees, this seems like a money grab.
Is there really a marginal cost to holding more money? Presumably they can buy treasury bonds and earn some interest off the holdings. In terms of data storage, is it really more expensive to store a positive number vs. zero?
I suppose that compliance might cost something. I don’t know what KYC laws they have to comply with, but that is the kind of stuff that needs actual humans in the loop
That said, I think the better answer is to send it to the state as unclaimed property.