19. A system comprising: one or more processors; and a memory storing instructions that, when executed by at least one processor among the one or more processors, cause the system to perform operations comprising: accessing a first profile of a first member of a social network, the first profile being accessed in response to an action that references at least part of the first profile; determining a similarity score that quantifies similarity between the first profile and a second profile of a second member of the social network; ranking the second profile of the second member based on the determined similarity score and based on an elapsed time since the action that references at least the part of the first profile; and presenting the second profile based on the ranking of the second profile.
19. A system comprising: one or more processors; and a memory storing instructions that, when executed by at least one processor among the one or more processors, cause the system to perform operations comprising: accessing a first profile of a first member of a social network, the first profile being accessed in response to an action that references at least part of the first profile; determining a similarity score that quantifies similarity between the first profile and a second profile of a second member of the social network; ranking the second profile of the second member based on the determined similarity score and based on an elapsed time since the action that references at least the part of the first profile; and presenting the second profile based on the ranking of the second profile. 20. The system of claim 19 , wherein: the action in response to which the first profile of the first number is accessed includes submission of an annotation that corresponds to the first profile; and the ranking of the second profile of the second member is based on the elapsed time since the submission of the annotation that corresponds to the first profile.