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.
IEO offers more sense of security than ICO because the exchanger itself will enlist projects that you can easily use using their platform. It can safer but it does not mean that it is sure that you will earn a lot. Just have realistic expectations when investing. All kinds of investments have risks on their own and it will be up to you how you will handle and accept those terms.