13. A computer program product comprising a non-transitory computer-readable medium containing computer program code for performing the method comprising: receiving information about an action performed by a user, wherein the action comprises at least one of creating or interacting with first content, the user associated with an interest graph and representative of interests of the user in a plurality of topics; analyzing language of the first content to identify lexical features of the first content; determining a topic of the first content based on the lexical features of the first content; and updating the interest graph to modify an attachment level in the interest graph representing an interest of the user in the topic of the first content.
13. A computer program product comprising a non-transitory computer-readable medium containing computer program code for performing the method comprising: receiving information about an action performed by a user, wherein the action comprises at least one of creating or interacting with first content, the user associated with an interest graph and representative of interests of the user in a plurality of topics; analyzing language of the first content to identify lexical features of the first content; determining a topic of the first content based on the lexical features of the first content; and updating the interest graph to modify an attachment level in the interest graph representing an interest of the user in the topic of the first content. 14. The computer program product of claim 13 , wherein determining a topic of the first content based on the lexical features of the first content comprises: comparing the lexical features of the first content to stored lexical features, wherein the stored lexical features are associated with one or more topics; and determining the topic of the first content based on the comparison.