Residents transfer money using the M-Pesa banking service at a store in Nairobi, Kenya, on Sunday, April 14, 2013. Trevor Snapp | Bloomberg | Getty Images

Oh, to enjoy the modern conveniences of Kenya. At least in the realm of cashless marketplaces, the east African country has been thundering along the cutting edge since the 2007 launch of M-Pesa—the M is for "mobile"; pesa is Swahili for "money."

What was originally conceived as an efficient method to make payments on microloans has been rapidly adopted by Kenyans as a way to send money from urban centers back to rural hometowns.

A husband working in Nairobi can send money home to the countryside with a couple of taps on his mobile phone. His wife can cash out at the increasingly ubiquitous shops with M-Pesa agents—the number of agents across the country increased 40 percent last year to more than 65,000—and she can also leave the money on her device to make digital payments with the hundreds of businesses who accept them. But what's been most surprising given M-Pesa's blockbuster success—19 million of Kenya's 44 million people subscribe, including more than two-thirds of the adult population, and a quarter of the country's economy flows through the mobile-money service—is how other countries have failed to replicate that success. (Read more: Cashless society? Not even close in US)

Everyone expected it to take the entire continent by storm. But the market in Kenya is so unique. Sunil Sachdev Managing director, Fiserv International Payments Group

Kenya's long-distance lead

"Everyone expected it to take the entire continent by storm," said Sunil Sachdev, managing director with Fiserv International Payments Group. "But the market in Kenya is so unique." Three conditions made Kenya particularly fertile ground for M-Pesa: high penetration of mobile devices; a killer application—namely, a cheap and simple solution to sending money home; and the presence of a dominant mobile carrier.

The first of these is a broad phenomenon: According to a Bill & Melinda Gates Foundation report, mobile penetration in Africa jumped from 3 percent in 2002 to 48 percent in 2010 and is expected to hit 72 percent next year. Formal banking services, on the other hand, have been used by a relatively elite few, leaving the door open to an alternate solution.

The killer app of facilitating money transfers to rural regions was somewhat unique and particularly well suited to Kenya, said Paul Makin, head of mobile money at Consult Hyperion, the lead consultancy in building M-Pesa for the mobile operator Safaricom.

(Read more: Paying cash costs Americans $200 billion a year) "Kenya is unusual in that it has a long history of domestic migration," Makin said. But people working in urban centers had no simple and inexpensive way to send earnings back home. "It could take three days to reach the families and sometimes never arrived. So the arrival of a system that could do it cheaply and within minutes was extremely attractive."

The third condition—a single dominant player—has proved elusive in other countries, partly because the wild success of M-Pesa has caused others to rush in and create fragmented markets. Whereas in Kenya Safaricom's M-Pesa enjoyed a snowball effect, in other countries it has been harder for the obvious choice to emerge—customers mainly want to use what everyone else is using, for the sake of convenience and usability. The result is that there are more than 200 similar systems in emerging markets, but only about 10 percent have achieved momentum, Makin estimated.