Want to Lower Your Cellphone Bill? Get Ready for Ads

Boost Mobile is about to find out if your desire to save $5 a month is stronger than your desire to see fewer ads on your smartphone.

The prepaid carrier has launched Boost Dealz, an Android app for customers of its mobile wireless service. The app displays ads and other special offers when you unlock your screen. Both Boost and Unlockd, the company that serves up the ads, say Dealz advertising will targeted to your location. In exchange for keeping Dealz active for 30 days, you can knock $5 off your monthly bill.

In its announcement of Dealz, Boost said the ads will show up "at various times customers unlock their screen." But if the ads end up being too frequent, they could try the patience of Boost subscribers. Unlockd says the Dealz app serves 40 to 50 ads a day, appearing one out of every three unlock screens on average. The app also uses your data plan to serve up these offers — about 80 to 120MB of data each month, Unlockd says.

MORE: We Rank the Top Cellphone Carriers in the U.S.

Still, assuming that Dealz offers don't show up every time you unlock your phone, Boost subscribers can potentially rack up some savings, particularly if they pair Dealz with other Boost offers. The prepaid carrier also takes $5 off your monthly bill when you use its auto-pay program, so a subscriber that sticks with both Dealz and auto-pay could wind up knocking $10 off his bill each month. That would bring the cost of a 5GB data plan down to $35 from $45.

The Dealz app is only one of the ways in which Boost is trying to draw more customers. The carrier also unveiled new family plans today (Jan. 26), joining Cricket and MetroPCS with plans for multiple lines. (Virgin Mobile, which, like Boost, is owned by Sprint, also offers a data-sharing plan, but only through Walmart.)

Under Boost's new family plans, two lines with 1.5GB of data each would cost $70. Adding a third line would cost an extra $20, while a four-line plan costs $100 a month.

For families who need more data, Boost also has a 5GB-per-line plan. Through Feb. 29, that's priced at the same $70 per month for two lines as the 1.5GB offer. Three lines with 5GB of data each cost $95 a month, while four lines under the 5GB plan cost $120.

A family of four would pay $100 a month on Cricket for 2.5GB of data on each line. MetroPCS charges $140 a month for four lines with 3GB of data each.

Through April 5, customers can get a free phone when they activate a family plan and buy a phone at one of Boost's stores. Available free phones include Alcatel's Onetouch Elevate, Motorola's Moto E, ZTE's Speed and the Tribute or Tribute 2 from LG.

Boost's move comes as the carrier find itself fighting with other prepaid providers to retain customers. Earlier this month, rival MetroPCS launched a promotion that targeted Boost subscribers by offering to cut their data costs in half if they switched wireless providers.