13. A system for providing effectiveness indications for social networking activity, the system comprising: one or more processors; and a machine-readable medium comprising instructions stored therein, which when executed by the processors, cause the processors to perform operations comprising: identifying a social networking activity performed in connection with a profile associated with a first user; identifying a plurality of actions performed with respect to the social networking activity by one or more other users exposed to the social networking activity, wherein the plurality of actions include explicit actions and implicit actions; for each of the plurality of actions, determining a total number of unique users performing said each action; calculating an activity score for the social networking activity based on the determined total number of users performing said each of the plurality of actions; determining a number of users exposed to the social networking activity; and calculating an effectiveness score for the social networking activity based on the activity score and the number of users exposed to the social networking activity.
13. A system for providing effectiveness indications for social networking activity, the system comprising: one or more processors; and a machine-readable medium comprising instructions stored therein, which when executed by the processors, cause the processors to perform operations comprising: identifying a social networking activity performed in connection with a profile associated with a first user; identifying a plurality of actions performed with respect to the social networking activity by one or more other users exposed to the social networking activity, wherein the plurality of actions include explicit actions and implicit actions; for each of the plurality of actions, determining a total number of unique users performing said each action; calculating an activity score for the social networking activity based on the determined total number of users performing said each of the plurality of actions; determining a number of users exposed to the social networking activity; and calculating an effectiveness score for the social networking activity based on the activity score and the number of users exposed to the social networking activity. 19. The system of claim 13 , wherein calculating the activity score comprises calculating the activity score based at least in part on a sum of the number of unique users performing one or more of the plurality of actions.