This week Sprint (NYSE:S) launched its latest promotion in an effort to steal customers away from the nation's top wireless carriers. The company's new campaign is called the All-In Wireless plan. It encompasses a monthly $60 price for unlimited talk, text, and data on either Apple iPhone 6 or Samsung Galaxy S6, plus the phone's $20 monthly lease price, for a total charge of $80 per month.

Sprint is essentially trying to simplify the cost for new and existing customers by letting them know up front the full expense of both the cellular plan plus phone leasing price. It is kicking off the promotion with a new ad campaign featuring David Beckham -- a friend and business partner of Sprint CEO Marcelo Claure -- trying to find a simple unlimited plan. 

The only other additional cost is the initial $36 activation fee. Of course, if you want a 64GB version of either phone you'll have pony up some more cash (come on, they can't give them away!).

The new All-In plan actually costs $10 more per month than the company's former iPhone for Life promotion, in which users could would pay just $50 per month for unlimited talk, text, and data if they leased a new iPhone through Sprint for $20 per month. Current iPhone for Life customers will be grandfathered in, so they won't have to pay the higher cost. 

So why add a new unlimited plan, particularly if Sprint already had one for the iPhone? Because the carrier is trying to find the right balance between offering unlimited plans and actually making money from them. 

The unlimited strategy
The All-In plan is still a good deal compared to all the other carriers. Only rival T-Mobile also offers an unlimited talk, text, and data plan; it starts at $80 per month, but, unlike Sprint's $80 plan, doesn't include the cost of the phone.  

By offering the new $80-per-month plan for the iPhone 6 and Galaxy S6, Sprint can lure people in who want the best smartphones on the market, give them unlimited data, and still increase the overall price it charges for unlimited plans by $10 per month for new customers. 

Sprint is not actually being sneaky here. Remember, former iPhone for Life customers get to keep the cheaper plan. Instead, the company is trying to improve its smartphone plan revenue while still staying competitive in the space. Verizon and AT&T don't even offer unlimited plans, and you'd be hard-pressed to find any of their plans that include the phone leasing price and call, text, and data costs up front. 

Where Sprint goes from here
In an interview with Re/code, Sprint Chief Marketing Officer Kevin Crull said: "There's a segment of the consumer base that really values unlimited. I think that need will be met. The pricing will probably move around a little bit."

This likely means we haven't seen the last of Sprint changing its unlimited plan pricing. In the most recent quarter, ended in April, Sprint pulled in $8.7 billion in revenue, down 7% year over year. And while the company has turned around its previous massive customer losses -- it managed 211,000 postpaid net additions in the quarter, compared to a net loss of 231,000 in the year-ago period -- it still has far to go in rebuilding its customers base.

Sprint formerly attributed some of its net customer additions to its iPhone for Life plan, and I think the company is attempting to take the success of that campaign and launch a similar (albeit a bit more expensive) deal for even more smartphone users.

By wrapping the unlimited plan with the cost of the phone into a single monthly price, Sprint will once again offer one of the lowest monthly smartphone plans on the market. If the company can continue offering plans like this, it could build back its subscriptions quickly. But don't expect the good times to keep rolling. At some point Sprint will again need to increase the price of its unlimited plan so it can actually bring those revenue numbers back up. But until then, Sprint customers can enjoy the low costs, up-front pricing, and, of course, the David Beckham promos.