1. A method, comprising: sending a sequence of pairwise questions from a server to a client device, each pairwise question in the sequence of pairwise questions soliciting one content item from a pair of different content items; receiving at the server successive responses from the client device to the sequence of pairwise questions, each successive response selecting a preference for the one content item in the pair of different content items in each pairwise question; sending the successive responses as feedback to an adaptive latent factor model for recommending content to a user of the client device; and receiving, after each successive response, a probability that the user will prefer another content item in another pair of different content items.