Based on many earlier picture titles, I would suspect that Dave (or one of his associates) picked this out as referring to "zephyr chills" - a wind bringing cold weather. Interesting that a patent medicine manufacturer would use such a slogan around the turn of the last century.

[The title refers to the giant ZEFF FOR CHILLS sign in the store window. - Dave]

Poor, lonely Zeff for Chills. No one wants to talk about it. Well, I'll give it a shot.
I wonder how advertising agencies down through the years would handle their advertising? First thing would be to suggest a new slogan, like "Zeff for chills, cures your ills," or "Zeff'll cure ya." (Obviously I'm not in the ad business.)

Or maybe they'd want to change the name, possibly ZEFFO. I can hear the jingle now, "ZEFFO, ZEFFO, ZEFFO, YOU'RE WHAT IT WAS MADE FOR." (I'm not a poet either.)

Anyway, I wonder how long this stuff was around to cure what ails ya. Was there some currently illegal stuff in it that just perked you up, like some popular soft drink? (No names, please don't edit this out, Dave.) Is there anyone still alive that ever took this stuff, whatever it was?

Come on, let's make ZEFFO the talk of Shorpy.

Zeff did not have much of an advertising budget, so it seems. Empty storefronts, and four years after this pic three sparse newspaper ads in January 1905, plus three more in May.

Worse yet, if they paid by the word, the May ads left out “and malaria”.