First, this is a carefully composed iconic image of mid twentieth America which manages to capture both the the interior and exterior of the coffee shop. It also includes a good view of a googie style sign and a color coordinated 1956 Ford Ranch Wagon. Although photographed in daytime, the interior has an eery resemblance to Edward Hopper's famous painting, Nighthawks.
Second is the style of the Krispy Kreme sign which does not include or resemble the Krispy Kreme logo. Even the word "donuts" on the sign and in the description on the postcard back does not match the Krispy Kreme way of spelling "doughnuts." Roadside Peek's Donut Delights has another example of a different looking Krispy Kreme "donuts" sign, plus some other good examples of doughnut signs.
In researching the address (3441 Central Ave., St. Petersburg, Fla.) I discovered an article, a day in dough business, about the donut shop at this address. This article was apparently written in 2001 when there was a Fray's Donuts shop at the location. A longtime employee informed the reporter that the shop was built in 1947 as a Krispy Kreme shop and the sign (reading Fray's Donuts) was the first or second big business sign on Central Ave. At the time of the article, the place had changed owners four times since 1947. Current directories list this address as St. Pete Donut House.
Another interesting thing about my Krispy Kreme postcard is that it was mailed in 1957 to Cadillac Showcase of The Price is Right TV show. According to Wikipedia, The Price is Right frequently featured a home viewer "showcase," for which home viewers were invited to submit their bids via postcard. I wonder how many other postcards survived from this and other sweepstakes and are now in postcard collections. My postcard came from a lot of advertising cards in a 1980s Barr's Postcard News auction.