In much of the world, shopping online involves browsing e-commerce sites or typing what you want to buy into a search engine. In countries where Internet-connected computers are a rarity, a Seattle-based startup called Slimtrader hopes to offer Internet shopping via text message instead.

Just like a conventional e-commerce business, Slimtrader relies on interactive databases to handle product inventory, pricing, orders, and payments. But unlike, say, Amazon, it has a database that users can interact with through short message service (SMS).

"Instead of searching for products with a computer, we make it possible to query a retailer's inventory by text message," says founder Femi Akinde. "You are sent the results and can then buy via text as well."

That could prove a hit in countries where shopping or paying bills means paying cash payments, and standing in a long line, he says. Slimtrader transactions draw funds from a person's cell-phone credit or can be provided using a prepaid or conventional debit or credit card.

The startup is working with partners including Microsoft and T-Mobile. Since July, the firm has been powering e-ticket sales for the Nigerian airline Aero, which wants to reduce the cash payments that currently make up the majority of ticket sales. This month, the company that runs ferries connecting Kampala in Uganda to Mwanza in Tanzania via Lake Victoria will also start using the system, allowing users to query the timetable and book tickets via SMS.

Slimtrader is one of a handful of startups hoping to ride the explosive growth of cell-phone connections in Africa and other emerging markets. These efforts are sometimes described as "social" enterprises, likened to aid agencies or nongovernmental organizations because they attempt to gain traction by helping low-income people. Akinde presented Slimtrader at the SOCAP conference in San Francisco this week.

But that doesn't mean they don't have the potential to make money, says Rachel Payne, Google's country manager for Uganda. She points to the success in Kenya of M-Pesa, a service developed by cell-phone giant Vodafone that lets users transfer prepaid credit between one another by sending SMS messages. With approaching 10 million users, M-Pesa is forecast to handle some 20 percent of Kenya's gross domestic product this year.