probably i'm missing here something
are you guys talking about buying directly to amazon and give your ebay costumer's adress so amazon will ship to that adress or are you guys talking about buying to sellers on amazon and give them your ebay costumer adress?

because if it is the first case, aint gonna be a problem that the box amazon uses has all over it "Amazon.com" stuff?! This way your costumer will know that he actually "bought" something from amazon and not from you.

if it is the second case, do the amazon sellers have any kind of ads on he's box ?! If they dont, this would be a great idea

TIA