Do car dealers really want to buy my car back?

I received a letter in the mail saying my car dealer wants to buy my used car because of current market condition.  The offer is attractive, and I went to the dealer to check out their offer too.  It's real. What's next?

If they offer to pay preminum for my used one, then so as the cost of new cars.  But it is funny that the dealer was willing to pay more than what I paid, even though I added 14,500 miles since.