There are plenty of great applications of crowdsourced data but the problem with this stuff is always incentivizing people to contribute instead of just consume

There are plenty of great applications of crowdsourced data but the problem with this stuff is always incentivizing people to contribute instead of just consume. It's a non-trivial marketing trick that products like Waze have managed (a big part of why Google didn't fold them into Maps entirely was to maintain the community), but it's certainly not a surefire thing.