Sprint (S) promised a major announcement, hyped the hashtag #SprintCountdown, and generally built up expectations that it would deliver some big news.

It was CEO Marcelo Claure taking a page straight out of T-Mobile (TMUS -1.11%) rival John Legere's playbook (minus the raucous audience and rock star entrance). The problem is that while Legere's Un-carrier media events introduce major new initiatives, Claure's announcement this week was that the company would be delivering almost exactly the same promotion it offered last year.

It's not that there's anything wrong with Sprint bringing back its deal where it offers to charge customers half what they are paying AT&T (T -1.19%), and Verizon (VZ -0.92%) while also adding T-Mobile this year. In many cases (though not all), it's a good offer for consumers -- specifically Verizon and AT&T users -- that will lead to them spending less money each month.

The disappointment in what Claure introduced Nov. 18 in a press release and a call with media came from over-promising and under-delivering.

What is the Sprint deal?
The company introduced what it called "the biggest wireless offer in U.S. history" in the press release announcing the deal. Sprint said it was "in celebration of the launch of its new LTE Plus network," and will offer the deal from Nov. 20 through Jan. 7, 2016. The carrier will also pay early termination fees to any customers who switch over and turn in their phones (which is general industry practice in most cases).

On the surface, the company is making a generous offer, but it's not as good as it looks, and there are some major caveats.

Sprint's offer comes with over 900 words of fine print. That's not atypical of any offer from most wireless carriers, but Sprint has lots of important details buried in the copy.

Basically, the company notes that its offer does not apply to T-Mobile's unlimited customers. It also explains that it matches the company's Simple Choice data policy of slowing down data speeds after the paid-for amount has been used. AT&T and Verizon customers won't get that offer. Instead, when they exceed their data allotment, they will be hit with overages.

This mirrors the existing policies from T-Mobile, which does not charge overages, and AT&T and Verizon, which do.

What's the catch?
While Sprint is saying it will cut people's bills in half, it will actually only be cutting the service portion. When it ran the same promotion last year, Re/Code reported that the savings worked out to closer to 20%.

The Sprint offer is also just a price deal -- it does not match whatever services users had on their previous carrier. This is something Legere gleefully pointed out in a series of social media posts:

Source: John Legere's Twitter feed.

The various Tweets also pointed out that Sprint does not offer free tethering, nor does it allow unused data to roll over. Claure's company is also not matching T-Mobile's offer of music and video streaming that does not count against your data cap.

Also, when Sprint offered this promotion last year, it included a number of ways users could lose the promotional rate. These included not paying your bills on time and, for a time, anyone in your family upgrading to a new phone. That was later dropped, though the company did not guarantee it would offer the half-off rate on the upgraded device, according to Consumer Reports, which called the offer "hard to get and easy to lose, which makes it half as attractive as it could be."

Sprint did not say whether it would pull the deal for a late payment in its press release or during Claure's announcement, and it's not mentioned in the fine print referenced above.

Don't believe the hype
In some cases -- specifically for AT&T and Verizon users -- Sprint is offering a pretty good deal. It's not a 50% off offer in the true sense of the word, but it should save some customers on all three carriers money each month.

In exchange for the savings, customers from the big two will be switching to a network that rated below AT&T and Verizon's on the latest RootMetrics report. Still, that may not matter as much as it used to since all four carriers have vastly improved their networks in the past few years. It's also not known how the company's new LTE offering will impact that.

For T-Mobile customers, the benefits are less clear. It might help some users save money, but others may not want to sacrifice perks like free tethering and the company's unlimited music and video services.

Sprint has a decent deal, here. It's just not exactly what it's saying it is, nor is it groundbreaking in the way Claure hinted at. It's hard to imagine that rehashing an offer will have a major impact on the company's declining fortunes.

The offer did help the company add a modest amount of customers last year, which is better than its normal loss of subscribers. It will likely add users again with this deal, though almost certainly fewer because the low-hanging fruit has mostly already been harvested.

Claure promised more, and if he wants to turn his company around, he needs to deliver it.