One would often assume that most western world countries pretty much follow similar trends. Australia's number one mens magazine is FHM- originally a popular UK magazine that really made its mark as the forefront in "Lads" magazines- that is, mens magazines aimed at the up and coming late teen-early 20's guy with a passion for scantily clad women, cars, pranks, beer and..well more scantily clad women. In fact FHM (and Ralph magazine, it's nearest competitior in Australia) can pretty much be responsible for the death of Playboy's Australian edition (it's still not socially acceptable to read Playboy on a bus or in a public place- whereas strategic nudity in Lads magazines is considered ok for your mum to find in your bedroom).
Soo.. what on earth would make the king of Lads magazines fizzle out in the US? Apparently it is because Americans turn to the internet a whole lot more for advertising than their other western counterparts. They also apparently are more subscription based; possibly meaning if you could subscribe to a magazine in the privacy of your own home, maybe you'd want something a lil racier..