prestidigital's Journal: What's the Deal with the Phrase That Pays?

A marker for future research and consideration...

What's the story on why every commercial radio station in America asks or "demands" call-in listeners to: "tell us your favorite station," or "what's the phrase thay pays?" What was the marketing angle on that when the concept first emerged? How, why did it become ubiquitous? Hypothetically, it must have been related to customer loyalty, or indelibly molding brands into listeners minds. But since literally every commercial radio station does this now, is the original point lost in the noise? If not, why not? Why, how is it still so important a technique? To me it really sounds like a bunch of radio stations demanding listeners to declare, "whooo's YO' DADDY?!"