is the Kennedy 1969-D really a key date? If so why? http://cgi.ebay.com/1969-D-KENNEDY-...61?pt=Coins_US_Individual&hash=item1e628df2b9
With a mintage of nearly 130 million it is a fairly plentiful coin. It is 40% silver but not worth much more than melt unless in very high grades.
The 1970-D is the key date in the Kennedy halves, which was not released for circulation. Just about anything that isn't made anymore (such as 40% halves, or wheat cents) qualifies for rare status for many sellers on ebay.
As Lyds said, that just insures that the listing will come up in more searches. Not a bad coin though. And at 6.50, that was a good buy as the melt is 5.59.