Jim Clark: pioneer of computer-graphics technology, cofounder of Netscape and web browsing, and now, an investor in a shopping-rewards app, Ibotta.

Clark is leading Ibotta’s second funding round, which is $20 million, and is also joining its board of directors. Ibotta, a Denver-based mobile company, provides coupons before people shop online or in-store and then enables them to transfer the cash from the rebates to their Venmo or PayPal accounts — or turn it into gift cards.

To unlock the coupons, shoppers complete “tasks,” such as sending tweets and posting on Facebook, watching a video, playing trivia, or answering poll questions. Once the coupon is unlocked, shoppers purchase the item with it and then receive the difference between the retail price and the discount in their Ibotta app. Shoppers can buy stuff either at partner or nonpartner retailers, though it’s easier to make purchases from companies that work with Ibotta.

Ibotta represents the future of how mobile technology will be used to drive both in-store and online sales. Not only does Ibotta allow retailers to drive sales directly in store, but it also allows them to see what type of media engagement has the largest effect on resulting customer purchases,” said Clark in an official statement.

“It not only builds loyalty through mobile media interactions but also allows brick-and-mortar retailers to drive and measure the increase in real traffic to their stores, down to the item-level purchase.”

Of course, digital coupons are nothing new. RetailMeNot was able to go public solely on the power of discounts, while Honey built a Chrome extension that hunts down discounts on products while shoppers are surfing the Web. And SwagBucks rewards people for watching videos, playing games, and various other activities, much like Ibotta, although its rewards come in the form of gift cards, coupons, and sweepstakes entries instead of cash. SwagBucks raised $60 million in new funding a month ago.

Ibotta’s app is available both on iOS and Android.

The company is partnered with 80 retailers in over 100,000 locations in the U.S, including Walmart, Target, Forever 21, Nordstrom’s, Best Buy, Sephora.com, Home Depot, and Petco, among many others.

Ibotta is headquartered in Denver. It previously raised an undisclosed amount of funding from Great Oaks Venture Capital.