I think no exchange is really free. You need to pay a minimum amount to be able to be listed at current exchanges. Also you can list with a large community supporting your project, that's the way I know so you can list at the exchange without having to pay
Yes, there are some exchanges which list coins depending on the number of polls. If OP has a strong project behind the coin or token and also if he has great number of supporters in their community than I am sure that some of the exchanges might consider listing them for free.
There have been a number of coins which also have started a number of exchanges which only keeps a few trustworthy and rest and left with minimum volume, no buy orders but excess sell orders, etc. Choosing an exchange is a important step and you should not always go for free exchanges in this case.
Moreover, never forget that there are a number of free exchanges who would promise to list your coin but might even run away with your tokens forever. Can you even imagine how riskier this might be for the future of the token or the coin?