Modifications for Flash Sales

Has anyone had experience with running a flash sale website?

Description here: http://amandaword.hubpages.com/hub/What-is-Flash-Sale-The-New-Business-Mantra

My questions:

  1. How does the eCommerce system tag the items to be in the sale?
  2. How does it open access to the item in the time frame?
  3. How does it give notice that the sale is over?
  4. How does it report results?