1. A method executed on one or more computing devices for providing a user with a set of user-generated labels for tagging an item, the method comprising: providing, via an electronic network, an item of online content for display to a user at a computing device operably connected to the electronic network; receiving an indication of a request from a user to tag the item; identifying a user-generated label set comprising a plurality of user-generated labels uniquely associated with and representing a plurality of sentiments regarding the item, each user-generated label of the plurality of user-generated labels being provided via the electronic network by a respective user, wherein the plurality of user-generated labels are selected based on the respective sentiments of the user-generated labels and respective fitness values for the plurality of user-generated labels, and wherein a fitness value comprises a weighted popularity of association of a respective sentiment with the user-generated label as a function of time; determining, for each user-generated label of the selected user-generated labels, display characteristics including a relative spatial position of the user-generated label with respect to the other user-generated labels of the selected user-generated labels based on a comparison of the respective sentiments of the selected user-generated labels; and providing, via the electronic network, the selected user-generated labels for display to the user at the computing device according to the determined display characteristics, wherein the user may select a user-generated label from the displayed set or input a new user-generated label.