Ikea in Sweden has created a site for all the traders and upgraders out there. I think it is a natural extension of the brand offer and it is good that they did it. It will hopefully make Blocket ( a swedish craigslist) a little scared if people start using it properly.
IIttala and Polarn o. Pyret have also created similar services. It is probably more brands doing the same out there ( please tell us if you know of any..)