New independent data shows Facebook enjoyed 153 percent growth year over year, while MySpace remains essentially flat. The site's growth is biggest overall outside of the US.

Overall, Facebook attracted 132.1 million unique users in June, compared to 117.6 million for MySpace, according to data from comScore released this week. Another site that saw impressive growth was Hi5, which doubled its unique userbase to 56.4 million.

ComScore's data seems to indicate that the market for social networking in North America has matured, showing only 9% year-over-year growth. But that's not the case elsewhere.

"The phenomenon is still growing rapidly in other regions around the world -- especially as the established American brands turn their focus to developing markets," the firm's executive vice president Jack Flanagan said.

Evidence of a large untapped global market can be found in the 66% growth rate in the Middle East and Africa, and 35% and 33% growth rates in Europe and Latin America, respectively.

MySpace is not taking part in the growth spurt, at least for now -- it has struggled to expand its business outside of the US. While it remains hugely dominant here, in many overseas countries it is barely registering.

Facebook is another story. Its growth is led by Latin America, which saw a eleven-fold growth rate: users jumped to nearly 12 million in June from just over 1 million a year ago. Similarly, Facebook more than quadrupled its user base in the Middle East/Africa and Asia Pacific regions, and tripled it in Europe.

Non-US users now make up an overwhelming majority of Facebook's user base -- 63%, in fact. This can likely be tracked to its efforts to localize the site: It's now available in some 89 languages, contributing to faster growth.

"By increasing the site's relevance to local markets through local language interface translation, the site is now competing strongly or even capturing the lead in several markets where it had a relatively minor presence just a year ago," comScore's Flanagan said.

Facebook's competitors seem to be pursuing a different strategy when dealing with international markets. Hi5 released tools to allow its users to localize the site into various languages, while supplementing it with its own work in translating services.

MySpace is doing things much differently. Instead of expanding everywhere and anywhere, it seems focused on developing markets where there are not only latent users, but also ad dollars. The company believes that this strategy is the more viable one for expansion outside the US.