Yet in experience-sharing communities the relation between individual efforts and the collective outcome is rather from the “total effort” type (all the reviews posted may be useful for consumers) whereas it is rather from the “best shot” for user communities (only the “good” answer to a given request is useful). However, whether the relation between individual efforts and the collective outcome is of the “total effort” or “best shot” type, the prediction about contribution is the same. There should be few contributors and many free-riders in both communities if agents simultaneously choose whether to contribute or not. However, the contribution issue fits better with a dynamic setting.