My comment was directed toward Amazon, not Amazon Warehouse Deals. Amazon Warehouse Deals is not the same as buying new from Amazon. Amazon Warehouse Deals sells "open box" and used product that was returned to them. From their website:Do products come with a warranty?"No. Used products generally do not come with a manufacturer's warranty but all of our items are backed by Amazon’s return policy. If you would like additional protection, you can purchase a warranty from Square Trade to cover certain items.". For any Dell product purchase from Amazon Warehouse Deals, Dell will look to the service tag number which will dictate the end of our warranty period. What is the service tag number?
I recently purchased a Dell U3415W from Amazon Warehouse Deals and had the warranty transferred to my name. While on the phone with Dell support, they told me that the warranty was for only 2 years. When I asked why, they told me I needed to talk to Amazon about it. I called Amazon and they could not give me any information about the warranty other than what's on the product listing page which is the standard 3 year warranty. Is there a reason I would not be given the full 3 year warranty by Dell? For reference, Chris states here that Amazon Warehouse Deals should get a 3 year warranty. 
U3415W Amazon Warehouse Deals and 3 year warranty