Methods and systems for estimating a probability of re-sharing information include extracting keywords from a set of documents addressed to a user. The keywords from the set of documents are weighted according a metric for the user's interest in the keywords' respective source documents to create an interest model. A new document having one or more keywords is received. A likelihood that the user will re-share the new document is determined. The likelihood is based on the interest model and the one or more keywords present in the new document. The new document is automatically responded to based on the determined likelihood.