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.
I think it's the same if the project's team do nothing for marketing or the IEO is conducted by a small exchange which has less customers. But at least, IEO will minimilize the fear of not getting listed on exchanges and that's the only advantage from IEO in my opinion 
Anyway, trading will more profitable if you understand how to do that.
yes I agree with I think it's the same between IEO and ICO because if both of them can harm us. IEO registered on small exchanges is difficult to get investors and the price of tokens after entering the exchange also often decreases. while ICO is also a lot of scams. so it is better to trade with clear profits or make long-term investments than to follow an unclear IEO or ICO.