[Fish]

Steve,
Huh???? Again, if we were speaking "technically", a deposit has nothing to do with whether an item is still for sale or not. As explained earlier, a contract is binding the moment that a live offer to exchange items of value is accepted. (but you can chose to word your offer so that acceptance must be indicated by way of deposit. heck, you can even specify in the offer that acceptance must be made by carrier pidgeon).
But your post does raise a good point. Just as a buyer is responsible to provide the agreed upon payment, a seller is responsible to provide the agreed upon item. If I had asked for a deposit in my offer, then yes, I would have a contract with the first person to pay that deposit. If I just offered my pump for sale (like I did) and agreed to sell it to a buyer... and then agreed to sell it to another buyer, because the first hadn't payed me a deposit and "technically the item is still for sale", I would be on the hook to provide a pump to both buyers who accepted my offer. Because I only have one pump, my options would be: buy a second pump to resell and fulfill my contractual obligations, or break my contract with one of the buyers and just hope he wasn't a miserable SOB like I am ( :
A good strategy to avoid being caught in an ugly situation like that, you could offer it to only one person at a time and close that offer before moving on to the next; or you could word the offer so that it was clear that the first person to accept, or the first person to place a deposit will get the pump. Again, a deposit has nothing to do with whether an item is still for sale or not, but you are absolutley right, my situation probably would have gone better if I had insisted on one... live and learn.

Cheers,

- Chad