I dont know about them either, so i cant tell if 400mil is too much or cheap. How do you know? i think your post was more stupid than their logo.
I know Waze is stupid because I have common sense. Unlike you. The original story explains what they are so you do know about them, and quite frankly, user generated data for GPS that requires user input is just a bad idea in every way. Drivers texting in speed traps, traffic jams, etc. will be worse than drunk drivers. Not exactly the kind of drivers that you want there to be more and more of, on the road, as this STUPID app gains popularity now that this story has come out.
You can read a good review and summary of why this app is such a bad idea here:
Waze, social-gps, should driving be a game?
"Waze encourages you to be a good social citizen by alerting other drivers of speeding traps, heavy traffic, road hazards, etc. The problem with this is that you become a road hazard if you’re driving and reporting a road hazard simultaneously. Texting while driving has been shown to have a greater impact on an individual than driving drunk."
Lastly, as for their valuation, they aren't even a household name like Instacrap and at least Instacrap was somewhat original. So that's why they aren't worth $750mil or even $400mil for such a poorly conceived app in a grossly over saturated GPS segment.