Texting Delays Mar Popularity Of $50 Boost Plan

He's been signing up 10 to 12 new customers a day on the plan, three or four times the number that came in before the Boost Unlimited plan was introduced in January. But a lot of them come back, "very irritated" about the text messaging problems, he said.

"This trend of a lot of people signing up to Boost is going to disappear really quickly if they don't resolve the texting issue," Kim said.

The new Boost Mobile plan uses Sprint's Nextel network, which uses a different underlying technology than the main Sprint network. Nextel users have complained of occasionally delayed text messaging for years, but the network's main selling point has been the walkie-talkie-like "push to talk" capability, used by work crews and emergency responders. Now the new Boost plan has opened the network to a new category of customers, for whom text messaging is more important.

John Votava, a spokesman for Boost, said the texting problems are due to the influx of new customers, and denied that there are long-standing problems with the Nextel network.

"The popularity of Boost Mobile caught us off guard. It overwhelmed our system," he said. The company has been working "day and night" to fix the problems, and aims to have the system "much improved" by next week, Votava said.