Define
The first line is a question the reader was already asking, or one they cannot leave unanswered.
Mechanism
Open loop plus recognition. A good question is the reader's objection, spoken first by us.
Verdict
We know the real objection and can answer it in the next breath.
Don't
The question is rhetorical fluff. If nobody needed that question, it is a wasted line.
Rights-cleared examples
Are You a Guesswork Advertiser? (4 page images)
Crisco vegetable shortening ad, Good Housekeeping 1932
Hoeveel blijft er over voor vrouw en kinderen?
How much shall we spend for advertising?
Is polite society polite and other essays by Mrs. Julia Ward Howe (1895) - poster
Is your child vaccinated
Is your child vaccinated Vaccination prevents smallpox
Lady Clairol Creme Hair Lightener ad, Modern Screen January 1960
Listerine Antiseptic halitosis ad, Ladies' Home Journal January 1949
Lyman Bryson, famous forum leader, will discuss "Are we done with democracy?" at Roosevelt High
New Lady Clairol Instant Whip Creme Hair Lightener ad, Modern Screen April 1959
Poster by Grün for the Café Riche, Paris, 1898