In summary, incorrect data. Not dirty reads, missing rows and duplicate rows. You can read entire chunks of data twice (or more). You can miss entire chunks of rows.
Fine for a dashboard where close enough is acceptable, not particularly good if users expect their data to actually be correct (most do).
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability