Virtela and its competitors generally rely on deals struck with facilities-based carriers and don't own much infrastructure. But Virtela adds performance management capabilities atop all the networks it pieces together to give customers end-to-end performance guarantees, Winther said.

In general, the VNOs and VNO hybrids can offer prices 15 percent to 20 percent below larger service providers, Winther said. "It's kind of like K-Mart versus Nordstrom."

The downside of working with a VNO is that it lacks the enormous resources of an AT&T, including a large support staff and the ability to leverage better deals with large carriers in countries such as China, Winther said.

The quickness Virtela showed Shaklee in Mexico is what defines an effective VNO, Winther said. "If you need a new telecom circuit in Hanoi, AT&T might say it will take three months, but Virtela might say, 'I can turn it on in 10 days,' " Winther said. "You might say you don't know Virtela and it's a risk, but even if you lose and they don't turn on the circuit in 10 days, you can still go back to AT&T."