What does pre-owned mean? There used to be another term for this, second-hand, but I'm not positive it has the exact same meaning(1). Those trying to sell you the thing aren't necessarily its owners and tend to want a piece of the action. Second-hand seems (to me, anyway) to be more direct, to eliminate (or at least bypass) such a middle-man. Nobody (yet, except in jest) directly offering to sell you one of their (by 'their', I mean 'first-hand') DVDs would refer to it as being pre-owned by them.
Even if it does have the exact same meaning (e&oe) I can't suppose that second-hand fell into disuse because somebody confused it with the faster moving pointer on a watch, sued, and won.
"You have been pre-approved for something we want to sell you" is another one. I can't see any functional difference between having been approved and having been pre-approved. Somebody likes you (aah, how nice). In the former case it's without your having to do anything, and in the latter it's after you've either drawn attention to yourself (or have acknowledged their attention) - maybe going through some hoops for them. The end result's the same - there's nothing standing in the way of your giving them your money.
Pre-ordering is another peculiar term. It seems to allow me to (apparently) order something before I order it. Even if that's not quite what it means, didn't we already have a term? We used to be able to reserve things. I don't think there's any subtlety of distinct meaning here, such as that between reserving something (which actually exists but is momentarily out of stock) and pre-ordering something (which does not yet actually exist). When I can pre-watch a DVD I might be more interested in being able to buy it in advance of its existence.
- The concept of 'same meaning' is open to discussion anyway. It's claimed - by Tennyson, I believe (and then Fowler) - that the only true synonym in the English language is gorse/furze but I'm not persuaded that a poet is necessarily an authority on semantics.