T-Mobile is giving away the company.

Starting tomorrow, every account holder with a voice plan will be able to claim a single share in the telecommunications company. New customers will also be eligible for a share. If you've been a T-Mobile customer for at least five years, you'll get two shares for every new customer you refer. Everyone else will get one share per referral.

T-Mobile CEO John Legere announced the stock giveaway during a live-streamed event in New York City today. Legere has rarely met a marketing stunt he doesn't like. But enticing customers with shares may be more than just another come-on. As federal regulators scrutinize another T-Mobile promotion—free data for select apps and services—giving away stock could help keep customers loyal.

The carrier claims to have more than 30 million postpaid phone customers. As of this writing, the company's stock is trading at $43.07 per share, which would make the stock giveaway worth about $1.3 billion if every customer participates. So far, the announcement doesn't seem to have had much impact on T-Mobile shares, which were down a little over 1 percent at today's closing bell.

To claim your share, you'll have to download T-Mobile's new T-Mobile Tuesdays app and sign up for a free account with online stock brokerage Loyal3. Customers will pay no brokerage fees to claim the share, Legere said. According to the giveaway plan's prospectus, T-Mobile's army of new shareholders will pay no fees to hold or sell the share for 12 months, after which time Loyal3 can charge a fee for selling the stock. You'll have 15 days to claim your stock.

Pizza Versus Data

In addition to the one-time stock giveaway, T-Mobile is giving away all kinds of more ephemeral schwag, from pizzas to movie tickets to a free hour of Gogo Wi-Fi on every flight. The giveaways are the latest in a series of promotions under T-Mobile's "Uncarrier" banner. But it's those earlier giveaways that have proven way more controversial than pizza.

In 2014, the company began allowing customers to stream music from certain providers—including Spotify and Apple Music—without having it count against their data limits. Last year the company expanded that idea to video providers, including Netflix and HBO, with the caveat that it would slow connections to all video content as long as the "Binge On" option is enabled—something the company wasn't entirely forthright about initially.

Exempting some service providers from data limits, a practice known as "zero rating," is controversial. Many believe the practice violates net neutrality—the idea that all Internet traffic should be treated in the same way by Internet providers. Although the Federal Communications Commission didn't ban zero rating outright as part of the sweeping net neutrality regulations it enacted last year, it did reserve the right to evaluate zero rating on a case-by-case basis when the practice affects competition.

So far the FCC hasn't ruled on T-Mobile one way or the other. But giving away free stock to its customers could be a way for T-Mobile to defend its consumer-friendly image if the company has to defend zero rated offerings in court. Perhaps more importantly, free stock could also serve as an appealing offer for customers should regulators ever ban T-Mobile from offering its zero-rated services.

Adding new customers is important for any business. But T-Mobile isn't just trying to turn a profit; it also has spent years trying to make itself an appealing acquisition target. Although the carrier's parent company Deutsche Telekom reportedly put plans to sell T-Mobile on hold while the FCC auctions off wireless spectrum, Deutsche Telekom has been trying to offload T-Mobile since at least 2011, when the Justice Department ultimately blocked a deal with AT&T. At the end of 2015, T-Mobile had fewer than half as many wireless subscribers as AT&T or Verizon. But it's growing rapidly, perhaps in part thanks to its ambitious perks. Whoever eventually decides to acquire T-Mobile may or may not keep the free pizza-and-stock train running. The important thing for T-Mobile is that it grows as fast as possible in the meantime.