More generally, an important direction for future research would be to investigate the
limits of UGC. For example, research has shown the value of Yelp and TripAdvisor for
restaurants and hotels. Will user reviews become the norm for doctors and cars as well?
The potential for reviews to proliferate in different industries likely depends on factors
such as the number of products or services being evaluated and the extent to which spe-
cialized knowledge is required to evaluate that product or service. There may also be areas
where UGC will never be feasible.
In addition, an important intersection between UGC and social goods has been
under-examined. While the areas of voting and organ donation are clearly important,
virtually every action we take