There are about 4.6 million frequent flyers of which 4% are Platinum and Gold status.

A silver frequent flyer is typically a male over 40 (but 30% are aged between 25-39). Flies up to 20 domestic return trips a year and up to 5 international return trips a year. They travel mostly in economy.

A goldd frequent flyer is typically a male over 40 (but a third between 25-39). Flies up to 32 domestic return trips a year and up to 10 international trips a year. They travel frequently in economy (especially when not travelling for business)

A platinum frequent flyer is typically a male over 40. Flies up to 70 domestic return trips a year and up to 20 international return trips a year. They too also travel frequently in economy.

In my other book (which I cannot find, but if I do I'll be sure to post the information) gave figures on how many people signed up a day etc.