1. A computer system for updating multiple presence publications using a single update publication batch request, the computer system comprising: at least one processor; and at least one memory, communicatively coupled to the at least one processor and containing computer-readable instructions that, when executed by the at least one processor, provide: a publication store component for storing collections, each collection comprising one or more presence publications, wherein each presence publication includes presence information comprising a user identifier identifying a publishing user and a collection identifier identifying a collection to which the presence publication belongs; an expire publication component for periodically removing expired publications from the publication store; a receive update publication component for receiving an update publication batch request, the update publication batch request including at least two publication updates wherein a first publication update comprises different presence information than a second publication update in the update publication batch request, the presence information of the first publication update including at least a first user identifier and a first collection identifier; an update publications component for updating presence information of the at least two presence publications in the update publication batch request, the update publications component configured to: (a) receive the update publication batch request from the receive update publication component; (b) select the first publication update in the update publication batch request; (c) locate a presence publication in the publication store component corresponding to the first publication update, the presence publication located using the first user identifier and the first collection identifier; and (d) update the presence publication with the presence information in the first publication update.