So, I stalked our Bed Bath and Beyond registry before the wedding and know for a fact that a significant number of gifts were purchased months in advance, but we haven't received them. We didn't have any no-shows at the wedding, either.
I called up the store and they said they don't track who bought what, whether it was online or in store, whether it was shipped, etc. They said if they have the name and phone number of the purchaser, they *may* be able to track the gifts down. Unless guests approach us and ask about the gifts, we have no way of knowing who purchased them. Obviously we can't send these people thank you cards, so now we look like assholes. And I don't know if we should buy them with gift cards, since it's possible we could still receive them.
This is the definition of a first world problem, I know. Still, frustrating.