If you're the type that doesn't like being locked in to a long-term commitment-whether it's a 30-year home mortgage, getting your college degree, or marriage-then you've probably been turned off when shopping for a cell phone calling plan. After all, most carriers today require a two-year minimum contract before they'll give you that free phone or discounted calling plan. Fortunately, there is another option that is gaining in popularity: the non-contract wireless calling plan, available in monthly or "pay-as-you-go" formats.

Unlike traditional calling plans that require a contract, these non-contract calling plans offer the option of paying in advance for a predetermined amount of minutes or simply paying for the minutes you use, whenever you use them. In fact, a new study by J.D. Power and Associates finds that the prepaid segment has changed dramatically during the past year, with many wireless carriers increasing their offerings of monthly plans-some of which mimic traditional contract plans, while others offer unlimited calling and texting.

To determine which prepaid carriers perform the best, according to current non-contract wireless service consumers who use their services, the 2009 U.S. Wireless Prepaid Customer Satisfaction Index Study measures customer satisfaction across six key factors. In order of importance, they are:

• performance and reliability (28%)
• cost of service (19%)
• account management (17%)
• initial activation (15%)
• offerings and promotions (12%)
• customer service (9%)

According to the study, more than 40 percent of non-contract plans are monthly plans, compared with less than 30 percent in 2008. In addition, overall satisfaction among users of pay-as-you-go plans (756 on a 1,000-point scale, on average) is considerably higher compared with users of monthly plans (742, on average), driven by satisfaction with the performance and reliability, and account management factors.

The study also finds several demographic differences that distinguish pay-as-you-go users from users of monthly prepaid service. The average pay-as-you-go user is older, more likely to be retired and has fewer wireless phones in their household. The monthly prepaid plan user more closely resembles the contract plan user-desiring a large network, mid-range feature phones and messaging, but without the commitment or penalties of a contract. Two-thirds of monthly plan users report that they have cut ties with their former contracted service carrier.

"As the non-contract wireless market continues to evolve, users need to be sure to explore all of the alternatives available to them in order to determine the appropriate plan to suit their needs," said Parsons. "With this increased breadth of options, wireless customers can find a plan that optimizes their wireless experience and meets their budget without requiring them to sign a contract."