The choice of the exchange for IEO is very important. It must be a lot of users on exchange that IEO will be successful.
Liquidity is very important for every exchange. It must be big trading volumes on exchange and a lot of traders.
Many exchanges has no liquidity and it is very hard to buy and sell crypto assets on them, that is why many traders do not work with such exchanges.
The absence of liquidity is a very big problem for many exchanges. There no traders on the exchanges that do not have liquidity.