Poloniex - not possible right now.

First user base has to grow. Then few non paying exchanges.

If traders decide to support this coin - remember they are in it only to profit - then more miners join the show.

Hashrate increases, price goes up general masses spot the coin, trading blooms - poloniex sees an opportunity to earn on trading fees. Also they are very picky about new coins. Xvg for example is having a good trading volume on bittrex every day, its 3 years old and still not listed on poloniex.