I sold a low value item on ebay this week and when I received payment I got a notice saying paypal would hold the payment for 21 days.

After an angry phone call to them I found out that it can be reduced to as little as 3 days if you provide a tracking number for the shipment, or until the buyer leaves positive feedback (24 hours after that).

This begs the question; what if I was hard up for money, sold an item expecting to ship it with the money the buyer provides, and then was unable to ship because of this nasty surprise?

Besides, this seems like just another one of those bank policies where they get to hold money for a period of time and therefore have additional capital to invest, etc.

Disgusting. The price of monopoly. More and more companies are being run like they are payday loanshark services or something.