AT&T’ CEO Randall Stephenson just served up a few details about his widely anticipated DirecTV Now national live streaming video service, planned to launch by year end.

The effort to turn the telco into a mobile video power — directly challenging cable — will offer more than 100 channels at “a very, very aggressive price,” he told the Goldman Sachs Communacopia investor conference.  And “the data required to stream it on your mobile device is incorporated into the price of the content.”

But not if you use a rival wireless service: “If you choose to use that in a mobile environment on AT&T [then] your data cost will be incorporated into your content cost.”

The company can make a compelling offering because “this is a very unique cost structure” that AT&T has “built from the ground up” with no set top boxes, online billing, and truck rolls. “It’s a nominal incremental cost to provision this.”

It also used its clout as the largest domestic television provider to secure low prices from programmers. “We were very aggressive about this over the last year,” Stephenson says.

Profit margins on DirecTV Now will be “thinner than what we’re accustomed to.” But that’s OK: “I’m willing to take thinner margins when there’s low capital intensity in the product.” And if it encourages customers to stick with AT&T’s wireless or wired services then “the lifetime value of a customer with this kind of product is very attractive.”

The company is about “90% there” on securing the programming deals it wants. “There are a couple of holdouts we’re trying to grind through and work through.”

Still, he figures that next year “this is going to be a big driver of revenue for us.”

He’s especially optimistic about DirecTV Now’s ability to help draw consumers into the AT&T ecosystem.

“They don’t like buying a DirecTV subscription and then having to go and pay extra to see the same data on a mobile device or tablet,” Stephenson says. “They don’t want to buy an over-the-top subscription and have to pay again if they want to stream it to a TV. If they forget to DVR Silicon Valley, the idea that I now have to go to Apple or Hulu or wherever I have to go to download it and pay for it again, when I’ve already paid for it on DirecTV — we have to solve that problem. We think we’re at a place where we have resolved that across several segments.”

The CEO acknowledges that DirecTV Now might cannibalize some of the company’s higher priced services.

“But that’s a good sign,” he says. “It means you have found something the market really wants.”

Still, the initial goal will be to sell DirecTV Now to about 20 million households that don’t subscribe to pay TV.

“We’ll be selling this product with one or two streams. These are people living in an apartment with one or two screens.”