A method comprising: by a first computing device, receiving for a first user of a social-networking system, from plurality of contact-information sources one or more instances of contact information in one or more categories of contact information; by the first computing device, automatically selecting one of the instances of contact information in each of the categories as a default contact information of the first user for use by a plurality of second users connected in a social graph to the first user; wherein the social graph comprises a plurality of nodes and a plurality of edges connecting the nodes, wherein a first node of the plurality of nodes corresponds to the first user, and a plurality of second nodes of the plurality of nodes each corresponds to a respective one of the second users; characterised in that the selecting of one of the instances of contact information as the default contact information is based at least in part on: determining which instance is most frequently used by second users to contact the first user; wherein the activity of second users with higher affinity to the first user is weighted more heavily than the activity of users with lower affinity to the first user, wherein the affinity is measured using an affinity coefficient, and wherein the affinity coefficient is calculated based on values assigned to one or more user actions and a value assigned to a relationship between the first user and a respective second user, and wherein each of the affinity coefficients represents the strength of a relationship between the first node and a second node representing a respective second user in the subset, wherein the relationship between the first node and second node is represented by an edge connecting the first node and the second node; and by the first computing device, providing, to a second computing device corresponding to a respective second user, the default contact information selected for each of the categories for use by the second user. by a first computing device, receiving for a first user of a social-networking system, from plurality of contact-information sources one or more instances of contact information in one or more categories of contact information; by the first computing device, automatically selecting one of the instances of contact information in each of the categories as a default contact information of the first user for use by a plurality of second users connected in a social graph to the first user; wherein the social graph comprises a plurality of nodes and a plurality of edges connecting the nodes, wherein a first node of the plurality of nodes corresponds to the first user, and a plurality of second nodes of the plurality of nodes each corresponds to a respective one of the second users; characterised in that the selecting of one of the instances of contact information as the default contact information is based at least in part on: determining which instance is most frequently used by second users to contact the first user; wherein the activity of second users with higher affinity to the first user is weighted more heavily than the activity of users with lower affinity to the first user, wherein the affinity is measured using an affinity coefficient, and wherein the affinity coefficient is calculated based on values assigned to one or more user actions and a value assigned to a relationship between the first user and a respective second user, and wherein each of the affinity coefficients represents the strength of a relationship between the first node and a second node representing a respective second user in the subset, wherein the relationship between the first node and second node is represented by an edge connecting the first node and the second node; and determining which instance is most frequently used by second users to contact the first user; wherein the activity of second users with higher affinity to the first user is weighted more heavily than the activity of users with lower affinity to the first user, wherein the affinity is measured using an affinity coefficient, and wherein the affinity coefficient is calculated based on values assigned to one or more user actions and a value assigned to a relationship between the first user and a respective second user, and wherein each of the affinity coefficients represents the strength of a relationship between the first node and a second node representing a respective second user in the subset, wherein the relationship between the first node and second node is represented by an edge connecting the first node and the second node; and