1. A method for selecting, from a set of content items, one or more content items to be cached, the method comprising: determining, for each content item in the set of content items, a respective probability of use value for the content item that is indicative of a probability that the content item will be used if the content item is cached, wherein, for at least one of the content items in the set of content items, determining the probability of use value for the content item comprises: determining predicted signaled factor information comprising information indicative of a probability that a set of signaled factors will be received; determining joint probability information comprising a joint probability of a combination of receiving the set of signaled factors and the content item being used by a user; and determining the probability of use value for the content item based on the predicted signaled factor information and the joint probability information; determining, for each content item in the set of content items, a respective value of caching the content item; computing, for each content item in the set of content items, a respective caching value estimate associated with the content item wherein the caching value estimate associated with the content item is computed based on the respective probability of use value for the content item and the respective value of caching the content item; and selecting, from the set of content items based on the respective caching value estimates of the content items, one or more content items to be cached.