Mig33 has built itself a good business by remembering that billions of people worldwide use the humble feature phone instead of newfangled smart phones. The latest evidence of that is the growth of Mig33’s virtual gifts business on feature phones; it’s up 400 percent in the second quarter compared to the first quarter.

Those sales are helping the company transform itself from a mobile voice chat service to a social entertainment service, as the virtual goods business model takes root in mobile just as it has in social networking.

In the second quarter, sales of virtual gifts reached 4 million per month, compared to sales of 1 million per month in the first quarter. The average revenue per paying user is above $1 per month in countries such as Indonesia, South Africa and India.

Mei Lin Ng, c0-founder and vice president of marketing, said the growth rate makes Mig33’s virtual goods platform one of the fastest-growing mobile virtual economies in the world. Now virtual gifts are one of the company’s revenue pillars, in addition to avatars and social games.

“Food items are proving to be especially popular, especially around holidays,” Ng said. “We’ve also had a lot of items related to the World Cup” and the muslim holidays.

Singapore-based Mig33 started in 2005 as a voice-over-Internet calling company and now has an audience of 40 million. It built a social network around that feature as well as chat and other social functions. But now the company is making significant money from virtual gifts, which are priced anywhere from 5 cents to $2, and avatars, or animated characters. You can send your loved one a satay (like pork on a stick) or emotion-related gifts such as kisses, hugs or flowers.

Mig33’s developers have made more than 600 virtual gifts, 450 avatar items, and four new games available on the Mig33 platform. They are available as mobile downloads, mobile WAP or web access. Later this year, Mig33 plans to expand to iPhone, Android and other smartphone platforms.

Mig33 has had its most success in Asia; its business is modeled on the virtual economies created by China’s Tencent and Japan’s DeNA. Tencent’s has more than 500 million users for its QQ chat service. Mig33’s investors include Accel Partners, Redpoint Ventures and DCM.