There are several reasons people invest in ICO.
For example:
- Buying bulk amounts of coins
- Buying directly from the company (not paying intermediaries fees)
- Buying before coins hit the markets (proud to be first)
But the main reason investors partecipate in ICOs is that they believe coins bought on ICO phase are cheap than coins bought when listed on exchanges. This is often true, but unfortunately not always. There are several cases where ICO price is far more expensive that exchange price. For example Monetha has been dumped hard after the ICO, despite their ICO was very successful and gained lots of interest from investors. Sometimes coins/tokens get listed on exchange and then their price collapse because early investors and bounty hunters dump the coins as soon as they get listed. Other times projects seem good at a first glance, but after a while devs reveal their incompetence and thus the project gets abandoned.