Looks like Capital One has partnered with Uber for a new promotion:
https://www.capitalone.com/credit-cards/cash-back/uber/
Get every 10th ride free up to $15 with Quicksilver® through March 2017.
Capital One and Uber have teamed up to help you get the most out of every ride. It's easy—you'll see your progress in your Uber app, your free rides will load automatically, and you can use them anytime you want through April 2017. Just add Quicksilver as your Uber payment method, and you're on your way to rewards!