The ICO itself is simply a way for a project to obtain funds.  ICO's are predicted to take off in 2018 (2017 was already huge).  ICO's are a form of venture capital so just like any other investment they can work very well or not at all.  Also, just like any other investment, I would suggest you do your research, but more importantly take a strategy of diversification because the big winners are usually the ones that did not look appealing at first and many times the ICO that looks fantastic has put all of its resources into image with very little substance. 

A key point is to understand the market price of the token/coin will react to how the company implements/executes its plan and the real world viability of the project (i.e. will the project have a significant real world impact - is there a need or use case for the project).