1. A method of placing a document in a multi-tiered index, comprising the steps of: monitoring, over a period of time, requests for documents made by users; wherein said requests are intercepted by a device on a network that is remote relatively to a location of said multi-tiered index; determining which tier of said multi-tiered index to place said document based at least in part on a frequency that said users have requested said document; and placing said document in said tier.