Sailhack said..
^^^ How do you get 'on' aBay though? Aren't you viewing the purchase via their app or webpage? If you want to get technical - you aren't really 'on' eBay. As a preposition, it needs more context as in "I bought an item that was listed 'on' eBay.
For some reason we've all decided that we are
on websites when we read them, not
in them, nor
at them, even though they actually come to us.
Also, I propose that the most senseless phrase in the English lexicon is "Here/There you are/go." when you give an item to someone. It makes no ****ing sense whatsoever