T-Mobile USA ranked highest in customer satisfaction among major wireless carrier-owned retail stores for a second consecutive time with a score of 723, performing particularly well with regard to quality of sales staff, price and promotions. Verizon Wireless trailed T-Mobile in the rankings by only 1 point.

The findings were part of the first volume of the J.D. Power and Associates 2010 U.S. Wireless Retail Sales Satisfaction Study released today.

Now in its seventh year, the semiannual study analyzes evaluations from customers who recently had an in-store wireless retail sales experience. Overall customer satisfaction with major wireless carrier-branded stores is based on four factors. In order of importance, they are: sales staff (49 percent); price and promotion (27 percent); store facility (14 percent); and display (10 percent).

Nearly 40 percent of customers who visited a wireless retail store in the past six months to replace or upgrade a phone from a previous carrier, switch carriers or sign up for wireless service for the first time now own smartphones.

The study found that satisfaction with the retail experience among smartphone owners averages 11 index points higher, on a 1,000-point scale, than that of traditional wireless handset owners, despite the fact that smartphones require additional service plan options and are more complex to operate. Smartphone owners are more satisfied than traditional handset owners in all factors, particularly with regard to the sales staff.

“The increase in smartphone sales will have a long-term impact on how carriers handle their customers’ needs,” said Kirk Parsons, senior director of wireless services at J.D. Power and Associates, in a statement. “These phones do require retailers to adapt by constantly training sales staff to keep pace with new features and offerings, but carrying out simple tasks, such as explaining the phone’s operation, provides salespeople with a great opportunity to optimize the customer’s wireless experience and fosters greater loyalty to both the carrier and store.”

The study found that owners of smartphones are 27 percent more likely to visit their carrier’s retail facility to inquire about a problem with their phone than are those with traditional handsets. In addition, smartphone users are 18 percent more likely to inquire about having their phone repaired compared with owners of traditional mobile phones.

Additionally, smartphone owners spend an average of more than one hour in the store during the sales experience, which is four minutes longer than owners of traditional phones. Smartphones require retailers to spend significantly more time carrying out tasks such as activating the phone. Sales representatives spend about one minute longer carrying out value-add tasks with smartphone owners, such as showing them how to operate the phone, than owners of traditional handsets.

“In general, wireless carriers are succeeding in adapting to the quickly evolving landscape by ensuring their sales representatives are highly knowledgeable about newer offerings such as smartphones and the high-speed data plans they utilize,” said Parsons. “As consumers continue to take advantage of the latest technology, it is crucial for sales staff to be knowledgeable about all phone models and service plans available and to continue to display a high level of courtesy and honesty during the sales process to ensure satisfaction levels improve.”