Update on the correction
John sent me this e-mail regarding my earlier post about the amount of data on the Internet compared to how much data Wal-Mart has:
For what it's worth, I worked for NCR for ~ five years, and sold their "Teradata Data Warehousing Solutions". I'd agree with you in being dubious of the claim(s) they're making - specifically that there are only 230 TB on the whole web.
However, 460 TB sounds about right as far as the Wal-Mart data warehouse. NCR always loved to puff up Wal-Mart's database accomplishments when trying to sell to other customers. NCR purchased Teradata for that specific reason - their expertise in massive data warehouses.
SO - 460 TB, very likely spot-on. Twice the rest of the web - likely bollocks.