Well many factors affect my decision to invest into any ico.
1st thing is a first impression and that first impression is a website. It needs to be fast and lot of information. Thats a sign that owner is serious person.
2nd is product it must be interesting and something new.
3rd is White paper. I needs to contain good information on the product!
Project team more or less.
I also like to read a bit about product into which im investing so i check forums, blogs and old news about it. But i do this only if i cant decide easily.