Write an horoscope for every sign every morning and publish them here every night, without saying which sign correspond to which horoscope. Ask users to take note of the most faithful description of their day. After a few month, publish the sign correspondence for every horoscope you've published and let users calculate the times they matched their sign to the "correct" horoscope. If they all match considerably more than 1/12, you might be onto something.
(this ignoring the challenge of defining "night" and "morning" for an international audience)
Comments
Write an horoscope for every sign every morning and publish them here every night, without saying which sign correspond to which horoscope. Ask users to take note of the most faithful description of their day. After a few month, publish the sign correspondence for every horoscope you've published and let users calculate the times they matched their sign to the "correct" horoscope. If they all match considerably more than 1/12, you might be onto something.
(this ignoring the challenge of defining "night" and "morning" for an international audience)