Shares of slot machine giant International Game Technology (NYSE:IGT) rose today on news that Harrah's Entertainment (NYSE:HET) agreed to buy at least 11,000 of its coinless-capable machines to support the national rollout of its "Fast Cash" gaming system.

The deal is one of the largest single orders International Game Technology has ever taken, which explains the nice pop and today's heavy trading volume.

It's certainly a nice bit of news for IGT investors, who own a top player and innovator in the gaming business. (Cruise the floor of just about any casino anywhere and you'll see a seemingly endless supply of IGT machines.) Shares of Alliance Gaming (NYSE:AGI), whose eTicket system Harrah's is rebranding as "Fast Cash," also rose slightly today.

But the announcement is also a further sign that cashless slot gaming continues to gain acceptance. While it has been around for years, casinos have understandably been cautious not to rush gamers into accepting this fundamental change in the way they play and win.

On a recent trip to Tunica, Miss., I was struck by all the cashless slots. While there's certainly something satisfying about coin slots -- perhaps it's the look and sound of all that money tumbling out of the machine, or the feel of toting around a plastic cup laden with coins -- it's certainly easier dealing with a few small slips of paper. The missing "spillout spectacle," meanwhile, is easily recreated with sounds and lights.

But it's also worth noting that, in this case, "Fast Cash" isn't exactly cash. First, it appears the tickets are nontransferable -- in other words, they can't be used in different Harrah's casinos. Second, they expire after 30 days. And third, while you can use them to tip Harrah's employees, they can't be used to purchase merchandise from the casinos. (This information comes from Harrah's website.)

While these aren't exactly revelations, they're the sorts of things casinos must contend with when managing customer expectations while changing the technology they use. In the end, however, today's news signals that coinless is indeed where the business is going -- and gaming aficionados should get used to it.

Dave Marino-Nachison doesn't own shares of IGT, though he does own shares of competitor WMS Industries. He can be reached at dmarnach@fool.com.