The difference between ICO and IEO is that after ICO it will be a quaranteed listing of the coin on the exchange. Very often after the end of ICO it was no listing on the exchanges and investors did not know what to do with such tokens.
It doesnt matter what the ICO or IEO project team chooses, the main thing is that the project be useful to society and have the opportunity to earn money on it

Do you think that this is not important, and most users trust precisely the project that conducts IEO since technically such a project is ready for work.
Now even such projects on the market can raise money from people simply then disappear, more than once it was both seen and proven.