The other factor which i consider is the team. Only invest in projects which have a very very strong and experienced development team as the team is the thing which will drive the projects to new heights.
I'm very similar in my approach to investing in ICOs or even just a altcoin that is already on the market. On top of the idea and team I also like to see a active community being built as well as active social media accounts that show the team at work on their project or promoting the project at conferences etc. A hard working Dev team is key to success for me.