As you know IEO trend is growing but i feel IEO is profitable only for those who invested in token sale but who have purchased altcoin after launched they suffer loss majority of the investors ,as the BTT and some other altcoin examples of IEO.
The problem about ICO is that most of them are failed projects and are not listed in the exchange so you are stuck with the priceless coins in your wallet. IEO is not that more profitable than ICO, it is just that the coin is listed in the exchange. By doing so, even if the project does not meet its promise deal with the investors if earning a lot more than the capital, at least your coin will be not stuck around your cold computer forever. In IEO, you can minimize your losses faster than waiting for the exchange of the ICO.