I am selling my used kitchen. Its only 12 years old and I am selling it as a whole. Cabinets, countertop, and appliances. Besides facebook and craigslist....what are the best sites to attract the right buyers for this product? Im thinking a flipper would be mostly interested. Its a killer deal...I just dont know how to get it out there. Thanks in advance for your help!

I'd try craigslist or any local equivalents.  But you have to realize there is very little value for a "used kitchen".  Twelve year old appliances are at the end of their life and have essentially zero value.  You would need to pay to get them hauled off if you replaced them.  The countertop is unlikely to come out easily.  If its granite or some such, it was templated and customized to the space.  If its formica, well, it was cheap to start with.  The cabinets have some value, but not much.  For one, they two will be damaged in removal and they will show all the wear they took while they were in use.  For another, they were selected to fit your space.  If someone had exactly the same layout as your space, they would work.  Even then they may not be the color or style someone else wants.  Realize, too, that fix and flippers tend to have cheap sources for this sort of thing and would not pay anywhere near what a homeowner would pay a kitchen fixing company.

Your best bet may be to donate the cabinets and appliances to Habitat for Humanity.