With the value of mobile payment transactions expected to reach $721 billion (US) globally by 2017, the slice of the pie for Bitcoin's taking is growing. This year alone, the value of mobile payment transactions is forecast to total $235.4 billion, a 44 percent jump from 2012's $163.1 billion, according to the latest figures from Gartner.

The leading uses for mobile payments are money transfers -- which are said to account for 71 percent of 2013's total transaction value -- and merchandise purchases at 21 percent. Though bill payments are expected to grow by 44 percent this year, their share is still low. By 2017, the research firm expects bill payments to make up 5 percent of total mobile payment value. Near field communication (NFC) adoption remains stalled; the report predicts NFC payments to account for 2 percent of this year's mobile transaction value and 5 percent by 2017.

Given bitcoin's volatility, no such forecast exists for the cryptocurrency, which has a market cap of about $1.35 billion as of Tuesday and can see $30 million worth of coins transacted in a single day. But BitPay CEO Tony Gallippi says there are limitations to mobile payments that bitcoins overcome.

"Mobile payments are a booming business with hundreds of companies spending millions of dollars to fight each other," he said. "But every mobile payment company has the same two problems."

The first, he says, is that mobile payment companies "are all walled gardens, and users cannot transact outside the walls."

Additionally, Gallippi, who is in London this week for a conference, said these providers don't work internationally. "I can have 10 mobile payment apps on the phone, but if I go to Europe, not a single one of them will do me any good."

"And for an international traveler, something simple that works is better than something slick that doesn't," he added.