A computer program product comprising a computer readable storage medium having instructions encoded thereon that, when executed by a processor, cause the processor to:
- transmit descriptions of recommended actions selected by an online system to client devices associated with users of the online system, each recommended action for presentation via one or more channels;
- receive information, at the online system, from one or more client devices identifying a description of a recommended action, a channel used to present the recommended action, and an action with the recommended action;
- retrieve information stored by the online system identifying a number of times the content item was presented by each of one or more channels during a specific time interval;
- determine a sampling rate for each of the one or more channels based on the number of times the content item was presented by each of one or more channels during the specific time interval;
- sample the received information describing presentation of the description of the recommended action by each of one or more channels, information describing presentation of the description of the recommended action by the channel sampled at the sampling rate determined for the channel;
- and
- store the sampled information describing presentation of the description of the recommended action by each of the one or more channels at the online system.