During the lunch hour at Bitcoin 2013, Tony Rousmaniere of Fairbanks, Alaska, walked up to the BitPay booth and asked to buy a few copies of Bitcoin Magazine.

"We only take bitcoin," warned BitPay CEO Tony Gallippi.

The transaction's first hurdle had arisen: Rousmaniere keeps his bitcoins on a USB drive, not in an online account that could be easily accessed with his smartphone. He considers going to the ATM being demo'd at the show to change dollars into bitcoins. Instead, a friend offers to pay for the magazine with his Coinbase account, telling Rousmaniere he can pay him back later.

Bryan Krohn, BitPay's chief financial officer, pulls up the transaction on his laptop: three magazines at $8.88 each, or 0.2164 bitcoins total. Rousmaniere's friend needs to scan the QR code with the Coinbase app on his phone. He tries, but can't make it scan. Maybe the app is looking for a bar code, not a QR code, he speculates.

The two friends head over to the Coinbase booth to find out what the problem is. After Coinbase reps show them the app really can scan QR codes, they return to the BitPay booth to try again. This time, the scan works on the first try. On his phone screen, Rousmaniere's friend confirms the amount he wants to spend. Moments later, Krohn receives confirmation that the 0.2164 bitcoins has arrived, and hands over the magazines.

Rousmaniere, who notes that the total price changed by about three cents -- thanks to fluctuations in bitcoin values -- from transaction start to finish, nevertheless thinks the whole thing is pretty cool.

"It's really fascinating how to watch all these really smart people try to figure out how this works," said Rousmaniere, who considers himself a futurist.

His friend notes with a laugh, "I do think it would be handy if there was a Coinbase rep everywhere I go."