An information database in communication with an information application comprises a plurality of marketplaces and {TAIL ~ a plurality} of listings respectively classified within {HEAD ~ the plurality} of marketplaces 
An information database in communication with an information application comprises a plurality of marketplaces and { TAIL ~ a plurality } of listings respectively classified within { HEAD ~ the plurality } of marketplaces
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH