Probably being blogged everywhere: Check out and listen to this WFMU broadcast:
This 1965 production was part of a series written and produced by Bert Tenzer. You'll hear the unmistakable voice of Mason Adams as the father of the Jacoby family. Each of the albums uses a mystery-drama concept to conceal the identity of the product being advertised, which is revealed with much fanfare near the end.
It's one of the most unique forms of advertising ever employed. Dealers were given a stack of these records, and customers could take them home and listen to them. In exchange for brining the record back to the store, the customer would receive a discount coupon for the product advertised. I've only come across three of them in my travels, but it's possible that more exist. Information on Tenzer and the records themselves is scarce, although this one turns up fairly frequently at record shows.