Even at a young age, Kevin Sproles understood the importance of listening to customers. Sproles was 16 when he founded Volusion, an Austin-based maker of e-commerce software that now has 180 employees and $22.5 million in annual revenue. In the early years, Sproles would spend hours a day on the phone with small-business owners who had signed up for his service, asking them how Volusion might improve, say, its customer checkout pages.

Now that Volusion has more than 20,000 clients who pay $29 to $179 a month for its software, collecting customer feedback has become more difficult. "I can't call up everyone to find out what they want," says Sproles, who is now 27. Last year, Sproles and his team, including Volusion's newly hired chief customer officer, David Mitzenmacher, began developing a formal process of soliciting and vetting customer suggestions -- as well as a system for quickly turning those ideas into new software features for customers.

Volusion started by sending out monthly surveys to customers. Along with a Net Promoter survey, which measures customer loyalty by asking whether clients would recommend the company to a friend, Volusion includes questions about which improvements customers would like to see.

To encourage even more suggestions, Volusion built its own online forum that lets customers submit ideas and vote for suggestions they like. It modeled the tool after Digg, a website that lets users submit and vote for their favorite online news stories and links. Last Christmas, one customer used Volusion's forum to request a mobile version of the company's software. "With the increasing popularity of smart mobile phones, we need to be able to create a mobile version of our store sites," she wrote. The suggestion received 36 votes from other Volusion customers. The company launched a mobile platform in March.

So far, customers have submitted more than 1,000 ideas and placed more than 11,000 votes on the forum. A group of Volusion employees from different departments meets weekly to evaluate the ideas. The employees typically consider implementing an idea only if it has been requested by enough customers -- at least 30 voters in the online forum or 10 percent of customers in the monthly survey. Sometimes the suggestions overlap. "Often, we get a bunch of ideas relating to the same feature," says Clay Olivier, Volusion's chief operating officer.

Once the group has approved a new feature, the company continues to involve customers in the development process. Volusion's sales and customer service reps follow up with those who made the suggestions and gather more information for the software developers. Although customers may offer opinions on very specific details -- such as whether a graphic should be on the right or left -- Volusion employees focus on figuring out why, rather than how, customers want a particular feature. Then the software developers get to work. Most features take from two weeks to eight weeks to build.

In addition to the suggestions that come through the online voting system, Volusion also collects suggestions during customer service calls. Shana Bentivegna, a Volusion customer who runs Organic Pet Boutique, a Jersey City retailer of organic pet food and supplies, often calls with suggestions. "I do a lot of brainstorming over the phone with the customer service reps," she says. During one conversation, Bentivegna complained that two fraudulent orders had been placed on her website. She asked about the possibility of flagging orders from online shoppers with suspicious IP addresses.

Her feedback helped spur the development of Fraud Score, a feature that assigns a risk rating to incoming orders based on several factors, including the shopper's billing address, IP address, and recent credit card activity. Volusion charges an extra $13 to $50 a month for the Fraud Score service, and more than 700 customers -- including Bentivegna -- have signed up since it launched in February. Bentivegna says Fraud Score recently saved her from shipping $250 worth of pet food and toys to someone who was trying to pay with a stolen credit card.

Customer suggestions have already helped shape many of Volusion's popular new features, including gift registries and batch order processing, which helps retailers fulfill multiple orders at once. "Ninety percent of the product development," Mitzenmacher says, "came from our customers."