Facebook is expected to announce its 500 million user milestone this week, making it a massively populated online network. As The Washington Post notes, that’s more than the population of the United States, Japan and Germany combined. Maintaining its growth and popularity, the fact that Facebook has gotten this far, making leaps and bounds over MySpace and all other competitors, Facebook doesn’t seem to be slowing down anytime soon.

That’s not to say that Facebook’s few years of existence has been a smooth ride–the last year has been riddled with growing pains. Facebook’s several changes to its privacy policy and monetization tactics has made this week’s milestone all the sweeter, as the social network has had to handle a lot of advocacy demands, international influences, the curse of Hollywood and most importantly, the education of its users. Striking a balance amongst all these aspects of growing a business is no easy task, but Facebook is managing. The Washington Post outlines it nicely,

“The Silicon Valley Web site is now the biggest online trust of our vacation photos, electronic rolodexes, and recordings of how we felt about President Obama’s candidacy for president, the ban on headscarves in France and the Lindsay Lohan’s rollercoaster ride with sobriety. Seventy percent of users are outside the U.S., and one-quarter of all users are checking in and updating their pages from their cell phones.”

These last two trends are important to note, with Facebook’s worldwide appeal and dedicated mobile presence. Both of these initiatives have helped Facebook to penetrate a global market, which was an early aim for the network and its CEO Mark Zuckerberg. Yet creating a digital tower of Babel has its own inevitable downfalls–the problem with being everything for everyone is simply that you cannot do it.

Millions of Muslim users are threatening to leave Facebook due to the network’s removal of certain religious groups in response to other user complaints, seeking out a niche website for their needs instead of a catch-all network that can be configured (and revoked) for personal needs.

The past year, while doubling its user base, has also given Facebook the headache of dealing with the repercussions of its privacy updates late last year. Changing users’ default settings was an upset that has yet to see an end, with class action lawsuits and reactionary networks cropping up in protest.

But this week’s upcoming announcement also demonstrates the staying power of Facebook, which has proven the usefulness of online networking for correspondence and marketing intentions. The mobile front is extremely important for Facebook as it continues to strive for global growth, having just reached the 150 million mobile-user milestone earlier this month. As Facebook becomes more of a mobile distribution platform, it will continue to become more of a service (dictated by user demand and consumer needs) than a mere communication tool.