Regrets? We’ve all had a few. But AT&T CEO Randall Stephenson said his big whoopsie was offering an unlimited data package for AT&T customers.

“My only regret was how we introduced pricing … Thirty dollars, and you get all you can eat,” he said at the Milken Institute’s Global Conference. “Every additional megabyte you use in this network, I have to invest capital.”

The additional megabytes started to pinch AT&T a bit more as iPhone users grew in number and in data usage. Also, those customers’ iMessage capabilities undercut the carrier’s text messaging business, a fact that didn’t go unnoticed by the CEO.

AT&T’s subsequent tap-dancing around the unlimited data issue was nothing short of a media-fueled consumer firestorm.

It all started about two years ago, when the company killed unlimited data plans for new customers. The carrier started offering tiered data plans: DataPlus, a $15-per-month plan that offers 200MB of data; and DataPro, a $25-per-month plan that provides 2GB of data. DataPlus users who went over their monthly data allotment had to pay $15 for another 200MB of data, and DataPro users had to pay $10 for another 1GB of data. Simple, right?

The prices got bumped up at the beginning of this year, and the company also made new allowances for hotspots and tethering.

But even after the price hike, heavy users were seeing slowdowns. The carrier was throttling data service for the top 5 percent of heavy data users in a given geographical area for each month. Due to widespread public outcry, AT&T slightly changed its position.

Now, you can use up to 3 gigabytes during your billing cycle before you get throttled — 5GB if you’re a 4G LTE user. The company doesn’t currently offer an unlimited data plan for smartphones.

“You lie awake at night worrying about what is that which will disrupt your business model,” the CEO told the conference audience. Apparently, mobile data disrupted AT&T more than anyone could have guessed.

via The New York Times’ Bits blog; pop top image via hyku/Flickr