A lot of things, you need to take in consideration a lot of things before investing beause there are a lot of scams in crypto and specially on ICOs right now, the most important part is their social media for me. You should look on their web page and find out about their team and verify them. Also verify their whitepaper and roadmap if they complied to it. If you still unsure you can go to a Youtube channel and if they have a youtube review, go see to it. And last if the coin is already live in the market exchange, if the strength of the trade demand is high and have huge of volume, surely that coin is promising.