1. A computer-implemented method to rank users in an online social network, comprising: determining, using a computer, a connectedness of a user on a social networking site based on a number of first-degree contacts of the user and a number of second-degree contacts of the user, wherein determining the connectedness comprises assigning a first weight to at least a portion of the first-degree contacts who have restricted respective connections with the user, and assigning a second weight to the first-degree contacts who have not restricted respective connections with the user; determining, using the computer, a number of first interactions directed from the user to at least one of the contacts by generating at least one of a matrix or a vector representative of an interaction between the user and at least one of the contacts; determining, using the computer, a number of second interactions associated with the first interaction and at least one of the contacts by generating or updating the at least one of the matrix or the vector representative of an interaction between the user and at least one of the contacts; and ranking, using the computer, the user with other users on the social networking site based on the connectedness, the first interactions, and the second interactions.