MSDN / OEM/ MAK Microsoft Keys - how long can they last??

[brendongl]

I was wondering all the keys which get generated from MSDN admin accounts etc....how long can they last for?
I have been buying keys to sell on my ebay account and its been going great.
But my concern is how long until they are no longer valid / show on the customers computer that there key is not valid for updates / etc....

I remember afew years ago a lot of my office / windows software would show a non-genuine popup, but this was like 6 months to a year later of me using it fine.

My main question is, is there a chance, after one of my customers successfully activates and installs there office 2016 pro on there computer, that it becomes invalid in a short period of time?? Can someone explain the logistics behind invalid keys, etc.

As much as i want to keep cashing this cow on my ebay store, i dont want to risk bad feedback / multiple refunds (Paypal only has a 7-day policy for digital goods so that's fine, but feedback can be left / changed within 90 days I believe)

[OmegaStarScream]

Trading them here isn't an option as you will get a negative feedback as well. MSDN keys are known to be revoked after a period of time and that's why people don't buy,sell them around here anymore.
As far as I know , keys will expire once your MSDN account licence expires with it.  see http://stackoverflow.com/questions/22067037/will-msdn-product-keys-still-work-after-the-subscription-is-expired & https://msdn.microsoft.com/en-us/subscriptions/cc137104.aspx for more info.