A recommender service that curates stuff on behalf of users and suggests that is a pretty good idea.

The throwaway term "algo" is not really a good one because it means different things from different people and often it means a centralized thing built into the protocol. 

 Whatever you call it, a recommender system like this naturally drives centralization. It doesn’t need to be (and shouldn’t) on the protocol level, though. 

 Is it worth the cost? 

 I don’t see how critical mass can be built without it