To me,both are birds o the sane feather,it is just some kind of re-packaging.IEO may not last for long because i see it to be more dangerous than ICO itself.
It's a way to fill the gap left after dying ICOs. It's also an upgrade of the system. Both investments are popular among people who want to gamble and are hoping to get rich fast. It's the same kind of people who at first invested in cloud mining then ICOs and now IEOs.
The difference between them is that IEOs are much safer. You won't get scammed but you still can lose all your money if the exchange gets hacked or shut down. If Mt Gox had an IEO in 2013 what would happen to your money in 2014?