Methods and apparatus are described for storing a plurality of objects in
a plurality of storage options. An importance index is generated for each
of the plurality of objects with reference to importance data associated
with each object. At least a portion of the importance data represents
relevance of the associated object relative to a population of users
interacting with the plurality of objects. Each of the objects is stored
in a selected one of the storage options with reference to the
corresponding importance index and a hierarchy of the storage options.
The hierarchy of storage options represents at least partial ordering of
the storage options with reference to economic costs and efficiency of
retrieval.