After the huge number of scams that were in 2018, investors have gained a lot of experience and now they are rare invest in ICO, preferring to invest in IEO.
Now there are a lot of scams too and conduction of IEO and listing on the exchanges does not guaranty the success of the project and raise of the tokens.
I think it all depends on what kind of exchange IEO will hold and how popular this exchange will be. I think if one of the popular exchanges to confirm the listing of tokens in advance it says a lot.
Listing of the tokens on big exchange costs a lot. Very often start ups that conduct IEO do not have enough money for listing tokens on big exchange.
Promotion costs a lot. Many cryptocurrency startups conducts tokens on different exchanges. Every exchange has its own base of traders.
Listing on ecxhanges costs a lot, promotion costs a lot, conduction of IEO costs a lot. To collect money on IEO cryptocurrency startup must spend a lot of money.
Now founders of the crytpocurrency startups wery often use their own money to create a product and they conduct IEO only when the projects is ready.
.