Anyone with any feedback on propay.com?

[Homerboy]

used for (very) small businesses to accept CC payments via phone.
My wife does lots of craft shows etc where a CC machine in-and-of-itself wouldnt be feasible, but people often ask if she takes CC for payment.

http://www.propay.com/account/howpropayworks.aspx

Seems like a nice solution to the problem at hand. Just looking for any feedback anyone may have.

Thanks in advance.