Ads with "Checkup"

Could someone explain why someone would send their amp in for a checkup? I'm having trouble believing this. Unless it's older than about 10 years it seems there would be no need.
I would use it as a way of reassuring a potential buyer that the amp was up to spec and had been checked out by the manufacturer.

Kind of like having a mechanic check out a used car. To make sure there aren't any trouble spots lurking below the surface. Such as a transmission about to blow.
So much can go wrong--some pieces I've had have been trouble free for years.---Some not so---. I figgure it had a problem and was cared for.--EVERYTIME I see this 'checkup' thing;I assume it went in for any other reason than just a checkup.But, hey I'm a suspicious kinda guy.---Oh, the guys that didn't send their piece in for a 'checkup'---They end up in the "disputes" colum.--'ya think?
In many cases,it's an item that is still under factory warranty to the original owner,but the warranty doesn't
transfer to the second owner.
It has been my experience that these ads often mean the product was recently sent in for repair and the owner has decided to sell the item.
I usually take it the same way as robert8409. I'm sure there are cases like Kinsekd, but I beleive they are in the minority. Maybe I'm just a glass half empty kind of guy, but I also belive it was sent in for repair and the owner decided to sell upon return.
well, I suppose any buyer could ask for a copy of the receipt showing all work performed.
Pushes the bounds of believability IMHO. Goes great with memorable lines such as "box opened to inspect contents only" or "selling for a friend".
i dont buy it for 1 second,i emailed 1 constant seller & asked why all his ads say just back from audio classics & i got the speech about making sure the gear was up to mcintosh factory specs but at the same time the items come with no guarantee,smells like hype to me.
I hear ya!
I've been looking at some vintage tuners over at ebay and many of the ads state that the unit has been checked by a technician, cleaned and all buttons and switches lubed.
Gives me the feeling that I'm the one who is being lubed.
I would feel more comfortable buying a used piece that came back from the factory after a check up than from the seller with out a check up. I suspect the reason for the check up was due to a repair, but I would think that the manufacturer would want to do their best to send the product back in the best shape possible. Regardless of the reason for the visit, I would have more confidence in a used product because of the visit. Of course documentation and confirmation may be in order.