Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

AT&T (T -1.37%) isn't known for its innovative culture. The mammoth telecom typically lets smaller industry players test the waters on new ideas first. AT&T follows suit only when those ideas turn out to work. And it just completed yet another "follow the leader" cycle.

If you sign up for a new AT&T plan today, you'll have to fight the sales clerk hard to get your hands on voice minutes. The company is instead pushing new customers toward so-called "mobile share" plans, in which your family or company share a pool of text messages and data downloads, but everybody gets unlimited talk time. Ma Bell does offer one minute-metered option, but it only comes with 450 minutes a month and likely won't be popular.

The change seems inevitable. Ten years ago, telecoms still battled over landline long-distance plans and collect-calling services. You might remember the "1-800-CALL-ATT" and "1-800-COLLECT" commercials of that era. Dial down the middle, anyone?

But long-distance calling is now assumed to come for free with any plan you choose, particularly in the mobile world. The battlefield shifted to mobile minutes and bonus services. Then Sprint (S) went all-in with unlimited voice, data, and text plans. T-Mobile US (TMUS -0.08%) followed suit with its "uncarrier" strategy. Even Verizon (VZ -0.68%) had to join the party last year.

AT&T kept dragging its feet. Your AT&T minutes kept rolling over to the next month if you didn't use them, but that trick couldn't make up for the allure of unlimited talk. I mean, even those limitless voice plans have become a sideshow; Verizon and T-Mobile customers are looking for better high-speed data plans these days. Those are still hard to come by.

Last week's earnings report came as an ice bath for AT&T and its owners. The company is growing slower than fellow Dow Jones (^DJI -0.98%) member Verizon. Sprint reports later this week, and T-Mobile follows in early November, but chances are that even the little guys are stealing customers from AT&T right now. What do they all have in common that AT&T doesn't offer? Unlimited talk, of course. So it's high time to hoist the white flag and give up on the idea of selling minutes.

AT&T and Verizon can't afford to rest on their laurels. The two Dow telecoms built a huge lead in the early years of mobile telephone, but Sprint and T-Mobile are starting to look hungry. The two smaller players are now better capitalized than ever before and come with management teams from diverse backgrounds. I wouldn't be surprised to see the ever-changing market forcing AT&T to provide some real innovation one of these days.

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