It all starts with the team behind a concept. If there is no passion in a team it will absolutely fail. Also check their background. Have they already succeeded in some way before?
What market are they trying to reach. If it is a niche market with big potential or a new fresh model in a crowded market, investors will be more likely to invest/participate.
After that I would conscider the businessmodel (are these guys able to generate money).
How are they spending their money. If they are spending money like a can of water in useless things, then a investors are not likely to participate. They want to make money... not wasting it :)