I exported my Products table from SQL Server to Excel, added in a couple dozen records by copy/pasting and editing the records that had been exported, and then tried to import them back into SQL Server via SQL's internal Import/Export wizard.
It kept telling me that fields couldn't accept NULLs, yet the fields were set up to accept NULLs.
Is there some trick to this? Surely there's some easy way to import 10,000+ items into your store?