Bloomberg reports that shares of Groupon jumped 12 percent today after Deutsche Bank analysts upgraded the stock, noting increased use of the company’s mobile apps. “Groupon is surprisingly the most mobile penetrated e-commerce company we track,” analyst Ross Sandler wrote in a research report. Sandler also predicted mobile will play a key role as Groupon’s overall revenue grows more than 50 percent from 2011 to 2015.

While still in its infancy, the market for mobile deals — a catch-all term that can include everything from location-based coupons to ads to mobile payments themselves — is tremendously promising, as I documented in this report  for GigaOM Research last year. And while the online daily deals market is largely commoditized, mobile is wide open — which is why on-the-go discounts are Groupon’s future. The space is already cutthroat, with heavyweights like Facebook, Google, PayPal and Yelp gearing up to take on a small army of smaller players. It’s far too early to predict any long-term winners here, but Groupon’s ability to stay in the lead in mobile is very promising.