Information Resources, Inc. (IRI) provides point-of-sale information from more than 11,300 grocery stores, as well as some 7,500 drug stores. Further information can be found on the WRDS website (see links below).
The data is accessible through Web query pages on WRDS, and as SAS datasets on the WRDS unix server, wrds.wharton.upenn.edu. WRDS covers 1983-1997.
IRI commercial website
WRDS Introduction (includes how to get an account)
WRDS Website (to request an account or to login)
WRDS Without Account (via Stern wireless, and on public terminals at Stern and Bobst Library)