According to this Businessweek article, men are reading less, and it's not because there aren't any magazines out there for them (Car and Driver, Stuff, Maxim) but they're really reading less. The top magazines for 2005 were all women-specific, and even Time's losses this year are attributed to "slow going at its major male-targeted titles like Sports Illustrated and Fortune.

Some argue that it's not that men are disappearing so much as that there have been no big breakthrough ideas since Maxim. To its credit, Time Inc. isn't relying on magazine-centric thinking. The best spin on its research is that men visit magazine Web sites more often than women do. In other words, men aren't migrating so much from the content of magazines as from the format. This would be better news if ad rates on the Web were as pricey as those in print.

I'm not too sure that it's the format, but could it be that men are genetically-predisposed to read RGB? Or is it the way information is presented on the web ("chunks") that makes the men like them more?

I think it's because it's free.