1. A method, comprising: identifying a web object for prefetching as a part of a web page; determining whether to prefetch the web object based on a success rate for the web object as associated with the web page; observing a plurality of child HTTP requests from a client computer associated with a response to a first HTTP request for the web page; determining a measure of success of the prefetching, wherein the measure of success is based on (i) whether the web object was prefetched, and (ii) whether the web object was later requested; and modifying the success rate based on the measure of success.