The past six months have marked a high-water mark for Facebook. The social networking platform is up to 500 million users and has been valued at as much as $50 billion. Further, one of the year’s breakout cinematic hits was The Social Network, about Facebook’s founder Mark Zuckerberg.

Compare all that to MySpace, the social networking site that will be forever tethered to Facebook in much the same way that Lou Gehrig and Wally Pipp will forever be linked. Today, in a largely unnoticed move coinciding with the Verizon-iPhone marriage announcement (by design), MySpace said it will layoff 47% of its workforce. This announcement comes on the heels of a recent rebranding of MySpace to “My_____”, a move no doubt intended to cater to the platform’s artistic and unshackled clientele.

Facebook and MySpace are clearly on diverging paths. The Facebook empire continues to rise to new heights, while MySpace creeps closer to near-certain death. But why? MySpace’s move to “My_____” signals a move toward freedom of expression, giving the users the opportunity to make the experience their own. Contrast this with the news today that Facebook will be instituting yet another wave of changes mandatory to all users. With this new round of changes that Facebookers must accept, comes a new round of security hoops to jump through for the privacy-conscious user.

It’s an interesting paradox. More freedom (at least ostensibly) leads to fewer users and less dollars. Less freedom leads to, yes, more privacy concerns, but also steadily increasing users and more money. So, clearly, in the social networking game it’s not all about freedom and privacy. Is it about functionality? Maybe, but MySpace offers a level of customization that Facebook can’t match.

And perhaps there’s the answer. Facebook is clean and familiar, despite a seemingly constant stream of mandatory design changes. If it works and looks good, people will accept restrictions, regulations, and the odd privacy breakdown. With the new round of changes, Facebook users will gripe and moan, and yet more people will sign up. And MySpace will watch from the outside, futilely offering more and more freedom to a target market that apparently wants nothing more than a rigid set of rules and parameters, artfully pixelated.