That’s an important omission, because we found that Boost and Virgin typically had the lowest-priced deals when we compared 152 national plans, as we reported in the September issue of Consumer Reports in “Prepaid pays off.” We searched through national plans offered by eight big contract and prepaid carriers for a range of sample cellular consumers using various amounts of voice, text messaging, and mobile Internet services. Prepaid plans from Boost or Virgin were the least expensive in nine of 11 comparisons. 

Major contract carriers were cheapest in only two trials—for the sample families we studied that needed four phones. T-Mobile and Sprint tied for least-costly in one comparison, while Verizon was lowest-cost in another. Our comparison, in late June 2009, covered national, no-roaming-fee plans offered by eight carriers: AT&T, Boost Mobile, Net10, Sprint, T-Mobile, Tracfone, Verizon Wireless, and Virgin Mobile. 

The more restrictive, exclusionary search by Billshrink seems to reach a different conclusion more favorable toT-Mobile. T-Mobile can’t say what percentage of online makeovers found T-Mobile to be the cheapest. But this summer, the company conducted 9,500 mobile makeovers at its retail stores, street fairs, and music festivals in Chicago, Dallas, Philadelphia, and San Francisco by encouraging people to visit Billshrink, and “about seven of 10 of those found that they would save the most with T-Mobile,” says Tom Harlin, a T-Mobile spokesman. 

“T-Mobile tends to have the most economical voice plans, and Sprint has the cheapest plans for text and data usage,” Kothari says. He notes that Verizon and AT&T are the premium-priced carriers. 

T-Mobile fails to mention that primarily-prepaid carriers aren’t included in its “Makeover” comparisons. 

Billshrink does provide minimal disclosure in a small search progress window with a “Continue” button, but it’s easy to overlook. The box suggests a massive search is underway with the words, “Searching millions of plan combinations from these carriers.” Below that, tiny logos of the big four cell carriers are displayed. (The carrier box covered only two percent of the area on our 12 x 7.5-inch laptop screen, and got in the way of the search results we were intent on getting.) 

The more straightforward disclosure that Billshrink should provide up front is buried deep down in the “Any limitations?” FAQ on its Web site: “Our recommendations are computed by reviewing the plans available from the four national carriers: AT&T, Sprint, T-Mobile and Verizon….we do not currently include US Cellular, Boost, MetroPCS, Cricket and therefore you would not see recommendations from those carriers, even if they may ultimately qualify as lower-cost alternatives” [emphasis ours]. Still left unmentioned are big prepaid carriers Tracfone and Virgin 

Does this make the T-Mobile Makeover promise misleading? We think so. “Yes, prepaid plans do tend to be low priced, but to be used nationally there can be roaming charges,” says T-Mobile’s Harlin. But Boost, Net10, Tracfone, and Virgin are national and, with some exceptions at Tracfone, they don’t charge roaming fees. 

Harlin pressed on: “The vast majority of Americans are on post-paid plans, and that’s where the best value is. You might be able to get lower out-of-pocket cost with prepaid, but most times you’re paying more per-minute or per-use.” That’s not what Consumer Reports’ analysis typically found with the winning prepaid Boost and Virgin plans. 

Kothari also wouldn’t say T-Mobile is misleading. But he did not want to necessarily endorse T-Mobile either, when we asked him. Billshrink plans to add Boost to its analysis and expects Virgin to be next in line after that. Boost is owned by Sprint, which is also in the process of acquiring Virgin. 

Did you do a T-Mobile Makeover? Which carrier did Billshrink point you to as lowest-cost? Did you switch? What do you think now?—Jeff Blyskal