The premise of Upside is simple enough: Reward business travelers with gift cards for being a little more flexible with their flight and hotel.

Pulling this off is a bit more complicated.

“When Priceline was created, we knew that flexibility would become an extraordinary asset in the modern commercial world,” Walker told Fortune in an interview. “We also knew that to really make it work you needed enormous software power and you needed all kinds of tools that didn’t yet exist.

“It’s one of those problems that rattle around in the back of your head, like an unfinished song. I’ve got the music, I’ve got this melody, but I’ve got to get the harmony just right.”

Now Walker can make that harmony, thanks to the falling cost of cloud computing, mobile apps, and big data, which allows enormous volumes of information to be analyzed. Walker even credits ride-hailing services like Uber and Lyft for changing the nature of business travel, specifically the willingness of people to stay in hotels a little farther away from their business.

“It was really only in the last year to 18 months that it was clear that all the pieces came together and we could actually finish what we couldn’t before,” says Walker, who will lead Upside along with several other Priceline (PCLN) alumni, including former CTO Scott Case and Tim Brier, the former president of Priceline Europe.

How Amazon took over the cloud:

Upside is working with several database content owners such as Expedia and Sabre, which act as clearinghouses for fares and schedules for airlines, to access the massive inventory of flights and hotel rooms. Upside then reconstructs the database with a new layer of analytics that focuses on flexibility. Upside pulls this all together and packages it in a mobile app that is designed to quickly show business travelers what their flexibility is worth by answering a few simple questions.

For instance, a business traveler might earn a gift card for staying at a hotel that’s farther away from a convention center or taking a flight that leaves 30 minutes earlier. When a business traveler uses the Upside mobile app to buy a flight and hotel package he or she can expect to get $100 to $200 in free gift cards, and international travelers will typically get twice as much, Walker says. Costs will be reduced between 5% and 15% for the business traveler’s company as well, according to Upside.

Users can also apply the value of the gift card to reduce the cost of their flight or hotel, a feature Walker says will be particularly appealing for individuals who own small businesses.

A $35 service fee is applied every time the business traveler books a package through the app. The service fee provides users with 24-hour customer service. Users can only book travel originating in the United States.

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The company will open up a beta version mobile app in mid-September to business travelers who sign up as VIPs, starting today. All VIPs will receive a guaranteed $150 minimum in free gift cards for every Upside package purchased this year.

Upside will initially launch with 30 to 50 different gift cards. These will not be the physical gift cards found at the grocery checkout line. These are e-gift cards, which are downloaded to the user’s mobile phone a couple of days after he or she buys a travel package on the app. Walker wasn’t ready to name which gift cards will be offered; however, he did say Upside is working with Blackhawk, one of the largest gift card suppliers in the United States.

Walker, who is chairman of research and development firm Walker Digital, believes every business traveler is going to want to see what his or her flexibility is worth.

“Why wouldn’t you want to know if it only take a couple of minutes and it’s sort of fun to see what it’s really worth?” Walker asks.

Upside’s target market is small and medium businesses, not the big, highly managed Fortune 500 companies, Walker says. And while the seasoned “road warrior” will certainly benefit from using Upside, Walker says the core customers will likely be people who travel domestically four to six times a year or twice a year internationally.

The real promise in Upside is the company’s flexibility platform, or engine, which can work in other industries too, including healthcare and consumer products, Walker says.

“It works in anything where there’s an extremely complex, ever-changing data set and where only you know what your elasticity trade-offs are worth to you.”