Bitcart drops Bitcoin for Dash due to speed and fees.

http://www.valuewalk.com/2017/06/bitcoin-as-a-method-of-payment/

"I quickly realized Dash is superior to its competitors for making payments. Its instant-send feature allows transactions to be made over the network instantly for a $0.10 fee for the consumer, around 7000% cheaper than bitcoin’s fee and many, many times faster."