Quotes Uncovered: Sizzling Steaks

Photo: Stefano A

Each week, I’ve been inviting readers to submit quotations whose origins they want me to try to trace, using my book, The Yale Book of Quotations, and my more recent researches. Here is the latest round.
Stan Hansen asked:

What about “Sell the Sizzle, not the Steak?” I have heard it many times but never have found where it came from.

The Yale Book of Quotations has this under the name of marketing expert Elmer Wheeler:

“Don’t Sell the Steak — _Sell the Sizzle!_”
Tested Sentences That Sell (1937)

Garrett Pendergast asked:

“Happiness is positive cashflow.” Any ideas?

Charles Dickens said this, although not in quite those words. The YBQ has this:

“My other piece of advice, Copperfield,” said Mr. Micawber, “you know. Annual income twenty pounds, annual expendicture nineteen nineteen six, result happiness. Annual income twenty pounds, annual expenditure twenty pounds nought and six, result misery.”
David Copperfield (1850)

Rowena asked:

“It’s not what you’re country can do for you; it’s what you can do for your country.” – JFK said this, but I read somewhere that a statement to this effect traces all the way back to Pericles. Any thoughts?

There are a number of precursors of Kennedy’s line. The earliest given by The Yale Book of Quotations is by Oliver Wendell Holmes, Jr.:

“We pause to become conscious of our national life and to rejoice in it, to recall what our country has done for each of us, and to ask ourselves what we can do for our country in return.”
Memorial Day Address, Keene, N.H., May 30, 1884

baltimore asked:

Fred I was wondering who said “I rather die on my feet, than live on my knees”

An article in _The Survey_, May 1, 1924, says: “The day he [Emiliano Zapata] was murdered, and the news of it reached Cuernavaca, a barefooted peon scratched with his penknife in crude letters on one of the posts of the Boarda Garden, the old Maximilian palace, the following: ‘Rebels of the South, it is more honorable to die on your feet than to live on your knees.'” The saying is commonly credited to Zapata himself (who died in 1919), but the recounting of the incident of the penknife-wielding peon does not make that attribution.
Do any readers have any other quotations whose origins they would like me to attempt to trace?