If Apple (AAPL) - Get Apple Inc. (AAPL) Report  gives its smart watch a wireless connection, as has been reported, AT&T (T) - Get AT&T Inc. Report , Verizon (VZ) - Get Verizon Communications Inc. Report , T-Mobile USA (TMUS) - Get T-Mobile US, Inc. Report and Sprint  (S) - Get SENTINELONE, INC. Report will get a shiny new toy through which to sell customers more data. 

Giving the Apple Watch its own connection to 4G LTE networks would allow it to become more than the little brother to the iPhone, since the smartwatch currently has to piggy-back on a phone to connect to networks. Even if health monitoring and other apps take off, however, the Apple Watch has a lot of growing to do before it meaningfully impacts the wireless carriers' top line. 

"Mobile operators will be extremely happy to see an expanded class of devices -- LTE-capable watches led by the Apple Watch -- able to be added to their unlimited or shared data plans," Rich Karpinski of 451 Research said in an email. "These are the types of devices perfect for today's data plans -- carriers will likely be able to book a few dollars per device (T-Mobile currently charges $10 per month for a wearable, though Apple might be able to cut a deal on behalf of its customers) with little to no actual impact on their networks since the amount of data sent to watches is likely to be small."

As the watch gets cellular connectivity, the utility of the device goes up dramatically, Roger Entner of Recon Analytics said. "You break that ball and chain," he said, which would be particularly liberating for jogging or other sports or situations where carrying along a phone is cumbersome. 

Video has become the killer app on mobile networks, however. "People are not going to watch episodes of 'Game of Thrones' on an Apple Watch, which they do on iPhones and smart phones in general," Entner suggested. 

But Apple and the carriers have to be careful about loading data fees onto smart watches, which have not been the most robust product category. Low renewals for tablet data plans hit Verizon in the first quarter, for instance, suggesting that consumers' appetite for data and connected devices has its limits. 

TheStreet Recommends

Apple does not break out sales figures for the watch. Strategy Analytics estimates that Apple sold 2.8 million watches worldwide in the second calendar quarter. By comparison Apple sold more than 41 million iPhones during the period.

"Say they sell 10 million watches a year [in the U.S.]," Entner said. If the carriers charge $10 per month per watch, that's more than $1 billion per year for the big 4 carriers to split. If they can push the charges up to $30 per month, they could divide about $3.6 billion among themselves.

The big four wireless carriers are on track to generate $175 billion in wireless services revenues this year, UBS projects.

"It's nice. Nobody will say no to it," Entner said. "But nobody will get a bump in bonus unless you are at Apple."

Apple is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or sells AAPL? Learn more now.

More of What's Trending on TheStreet: