it's unclear to me whether you need a merchant account to use square; i'm assuming from "0-$60 in under 10 seconds" that you don't.

if you don't need a merchant account, the market for this is massive. there are millions of people who provide services and sell products who take cash, check, or paypal only. many of these people are dying to take credit cards with zero hassle, which square lets them do.

I thought about that too. Someone has to have a merchant account, so it's possible all of the payments go through Square and they act as a clearing house where they redirect payment to the correct merchant. I could see that leaving them vulnerable to chargebacks. I wonder what kind of rates they're offering to users.

from http://www.techcrunch.com/2009/12/01/square-worth-40-million...:

"like PayPal, Square allows anyone to have a virtual merchant account and take payments directly."

yep, the market is huuuuge.

The sex industry could be a large market.

In such a market, anonymity is probably preferred.

Gift Cards. See things like http://www.swapagift.com/ And http://www.valutec.net/

Be careful though, under US law since 2001, you are probably committing a financial crime by doing anything that looks like anonymous digital cash.

Probably. But maybe less so in transactions that are not illegal.

Could be :)

Something like this could get merchants who don't traditionally accept credit to start

Is it cheaper than getting a terminal? The idea behind this is you already have a cell phone. Why by an additional device to do this, which worse yet has a bad interface and can't be upgraded.