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For the first time ever, Domino’s surpassed $1 billion in digital sales in the U.S. over a 12-month period. To celebrate—and pump up e-sales even further—the chain is offering a 50% off pizza deal. Only, of course, for customers who order online.

Consumers have embraced e-commerce in waves. By now, the time when shopping online felt like a novelty is a distant memory. Most people today are completely comfortable booking travel via the web—it’d probably feel awkward and bizarrely inefficient to call up and reserve an airline ticket—and we’re all quite accustomed to ordering books, DVDs, toys, sneakers, electronics, and most other goods online.

It’s taken quite some time, though, for a broad swath of consumers to take to ordering restaurant food for delivery or takeout online. On the one hand, it seems like such orders would be a perfect fit for digital. Online ordering eliminates the need for a customer to wait on hold on the phone, and consumers can view menus and see orders on screens with their own eyes to double check for errors. On the other hand, restaurants needed to build systems that smoothly, efficiently, and quickly accepted online orders. For a while, it seemed as if consumers were skeptical about ordering digitally; the assumption was that it was easier and quicker just to call up.

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At least in terms of major restaurant chains that specialize in delivery, it looks as if we have now reached a turning point.

Earlier this week, Domino’s announced that from April 2011 to 2012, it reached the $1 billion mark for digital sales for the first time. Domino’s digital ordering services debuted in 2008, and have expanded especially quickly in recent months, with an iPhone app introduced last June and an Android app made available last February. Lately, more than 30% of Domino’s sales come from online orders.

As a reward to its e-customers, Domino’s is offering 50% off pizzas for orders placed digitally—via website, mobile, or smartphone app—now now through Sunday, June 17. The press released stipulates that the “limited time offer applies to the pizza portion of orders only” (meaning: wings, cheesy bread, and other items aren’t discounted), and that the discount is applied only to “pizzas ordered online at menu price” (meaning: the 50% off can’t be combined with specials or coupons).

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Curiously, what the release doesn’t state is that a coupon code will help customers get the 50% off discount. The code is listed at dealnews and other sites, though: Fittingly, it’s simply “50OFF.” Punch that in if the half-off pizza discount isn’t automatically applied.

Brad Tuttle is a reporter at TIME. Find him on Twitter at @bradrtuttle. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.