I believe you need to pay to be listed in bittrex. Unless they see a lot of volume coming in the future and get a lot of profit from trades.
Yes, you right here. MART has huge trade volume on Yobit, Bittrex should recognize that very soon.
It will be bittrex lost if they won't add MART. Some trading sites are gaining foothold due to some heavy supported coins not being listed at big known sites like bittrex.