Listing of tokens and change of ecxhange is very important for traders. After the listing of tokens on big exchange usualy price of the tokens raise.
First of all exchange must have a good liquidity, a lot of traders and big volumes of trade. If it will be a small exchange it will be hard to buy and sell tokens.
To have a lot of traders on the exchange, exchange must have a comfortable platfom, good conditions for trade and a lot of promotion.