It was sent to Roy Leonard at WGN Radio in Chicago. Roy Leonard was a radio host from 1967 until 1998, focusing on the World of Entertainment. Leonard interviewed some of the biggest names in the entertainment industry, many of whom referred to him as the best in the trade.
1972 was the year that Burt Reynolds caused a big stir by posing nude for Cosmopolitan magazine. I don't know if Roy Leonard was interviewing Burt and offering a date as a prize or if this card came entirely unsolicited. I'm afraid we'll never know why she was thanking him in advance, but the picture on the front of the card may be suggestive.
The message reads:
Dear Burt:
Thanking you in advance - I admire you mostly for your honesty on talk shows and your Body aint bad neither
love - Envy Johnson
love - Envy Johnson