Particular embodiments detect events associated with information about activities that a user has engaged in. The activities may be associated with a location or location-agnostic. Based on the received information, the social-networking system sends the user a request for follow-up information after an appropriate time delay. The time delay may vary based on the user activity and the context of the event that triggered the request. After the follow-up information is received, such information is stored in the social-networking system and may be used to determine recommendations, sponsored stories, advertisements, etc. to send to friends of the user. The information may also be used for ranking or filtering recommendations.