eBay Hates Sellers
I’m personally convinced that eBay hates its sellers, an ironic proposition that seems to undermine its primary business model of creating an online marketplace. My personal recent experience had a bidder win their auction for an iPod touch and then … not pay. I sent an invoice, and emailed the buyer, but got nothing but silence. Interestingly, buyers have 4 days to pay, so from 12/12, I had to wait most of the week before I could relist. I finally sold it again on the 22nd, but, what a waste of 10 days. Someone could have bought it in time for Christmas if eBay had a same-day payment policy.
Also, if your buyer doesn’t pay, you can’t submit bad feedback:
Sorry, it’s not possible to leave feedback for this transaction.
Feedback has been disabled because payment was not recorded.

I don’t see how “failure to pay” shouldn’t be a permanent black mark in their feedback history–it’s pretty egregious; sellers have a right to know.