One reason for Uber's success is that it removed the friction and pain of paying for a taxi. However a service that requires a mobile phone and credit card doesn't work for the under and unbanked. In emerging markets where cash is king, Uber has realized that there is still great utility in the ability to use a cellphones to hail a cab. Uber created a cash option for these markets. This new cash option is now available in 10 markets, but will expand to others where credit cards are not as ubiquitous.
It’s been successful enough that it has led Uber to continue growing its cash payments. Moving outside of its initial market, Uber has recently added cash options in 10 markets, including in India, most of Southeast Asia, Kenya, Nigeria, some of the Middle East and Peru. Uber has plans to continue expanding the cash option, too. The reason, of course, being that, in many regions around the world, particularly the underbanked and unbanked regions, cash is still king. “We recognize that not everyone uses a credit card, and there are different payment mechanisms in different places. We want to be able to serve everyone so, fundamentally, everyone needs to accommodate our system or we need to accommodate how riders in other markets pay,” Asia-based Uber executive Mike Brown told TechCrunch.
http://www.pymnts.com/news/payment-methods/2016/uber-cashing-in-on-cash-payments/