What drives up prices of shared power banks?

Shared power banks were once hailed as the answer to drained batteries on the fly and battery anxiety, but today, users find themselves frowning at skyrocketing prices. The power bank industry is charging ahead, but for how long and at what expense to the consumer? / 'Ma mian qun' becomes the go-to skirt for China chic (18:06). On the show: Heyang, Xingyu & Josh Cotterill