This probably happened to you all too. Hopefully not, but sadly I assume it did.
Our Drugstore.com order said that the backordered items could not be fulfilled and was cancelled. Funny, because when I ordered them, I specifically tossed backordered items out of my cart for items that were not on back order.
Truth is, they didn't realize the coupon that they put on their site would result in so many redemption and freebies. Not sure why it matters though, as I am sure P&G is re-paying them just like a regular store would. So I am sour on Drugstore.com and probably will not buy from there anymore.