Yea, I don't think novelty is quite the exploitable niche though. The uncertainty regarding whether or not something might become some sort of fad is way larger

Yea, I don't think novelty is quite the exploitable niche though. The uncertainty regarding whether or not something might become some sort of fad is way larger than whether or not some app with a clear use and target demographic might become at least ramen profitable, if not successful. Plus, there's no clear inference from successful novelty goods or services to what other possible novelty stuff. Someone might make a better text editor than the ones currently out there. But can anyone improve on the Pet Rock? It's a quite hard problem.