This week Asia’s social media scene has passed two significant landmarks with the news that Indonesia has leapfrogged the UK as Facebook’s second largest market while the region itself has exceeded 100 million members, which equates to roughly 20 percent of the total global figure.

First, details from Inside Facebook on Indonesia, whose Facebook numbers have been threatening to overtake the UK for a while now:

Indonesia, a Southeast Asian country that has nearly tripled its number of Facebook users over the past year, has finally eclipsed the United Kingdom as the second-largest Facebook market behind the United States. Its growth underpins Facebook’s emerging strength in Southeast Asia, a region has become strategic, rife with opportunities to push virtual goods and Credits.

The graphic from Facebakers, a Facebook measurement site, shows Indonesia in its new position, while emphasising its recent growth over the last three months, a rate that is only eclipsed by fellow Asian country India, where Facebook is set to open an office this year:

Inside Facebook explains how the growth of the social network has lead public figures, many of whom were initially skeptical of it, to embrace it as a means to communicate with the country at large:

Facebook continued growing, adding more than 17 million users in a single year and politicians and leading religious figures have come to embrace the site. The country’s president Susilo Bambang Yudhoyono has more than 480,000 thousand fans for his Facebook Page. Some of the country’s top Muslim clerics have started Pages too, like Chairul Tanjung, who sits on the board of Indonesia’s highest religious authority, the Indonesian Ulema Council.

As with much of the growth of social media in Asia, mobile has been a key driver which will become even more crucial in the future:

Facebook also boasts 67 percent Internet penetration among the country’s 45 million Internet users, according to the country’s ISP association and data on the company’s users there. In addition, the country has a growing number of people accessing the web via mobile devices — about 9 million, according to Onno Purbo, a longtime information technologies activist in the country.

So Facebook’s mobile apps and 0, it’s low-bandwidth mobile site, will play an increasingly important role there. While the iPhone leads Facebook’s mobile presence globally, in Indonesia, Nokia is the device manufacturer with dominant share in the country. Blackberry and Android are also gradually closing in.

On the subject of growth across the wider Southeast Asian region, whose countries have consistently ranked amongst the world’s fastest growing this year, Inside Facebook comments:

Anecdotally, developers tell us that social gaming is an important factor powering Facebook adoption in the region. And Facebook has moved to capitalize on that through a recent deal with Malaysian payments company MOL, which also has a presence in Indonesia.

Consistent growth in Asia, led by Indonesia and India, who contributed 3.5 million of the 10.1 million new members last month, has seen the region top the 100 million mark for the first time as reported by Malaysia-based digital media blogger Grey Review.

From the blog post comes the below graphic which neatly summarises Facebook membership and recent growth in all Asian countries:

For those who may question the significance of such news, aside from illustrating that Asia’s voice and influence on ‘the global internet’ continues to grow, the news is a wake-up call for business in the continent. Recent articles and reports that shown a slow adoption of social media marketing from business across the continent, but now with more than 100 million users on Facebook alone – which doesn’t include China were it falls foul of state censorship – clearly demonstrates the potential of the new media channels.

It is also interesting to note just how significant a driver Southeast Asia is. Recent research from Gartner suggested that ‘westernised economies’ in Asia, which are dominated by Southeast Asian markets, are adopting western social networks at the most rapid rate in the continent. It is clear from the graphics that Southeast Asia is continuing to propel Facebook growth, although India is gaining huge momentum while Japan and South Korea – identified by Gartner as difficult markets – are showing the kind of growth that might see Facebook rival both countries’ dominant, domestic-focused social networks.

What is for sure is that, like Indonesia, Asia as a whole has the potential to grow  further still with mobile the key factor.

Could the continent be the biggest influence in Facebook’s drive for a billion users? Mark Zuckerberg certainly believes so.

What is for sure, is that the significance of Facebook’s growth in Asia will have as much (if not more) of an effect the region as it has on the social network itself: particularly if Facebook makes more announcements like it made yesterday. Via the BBC:

Facebook has set out a strategy to make it as dominant a force in the world of mobile as it is in social networking.

At the heart of its plans is making the mobile phone a more social experience and offering shopping discounts.

The company announced the opportunity for businesses to offer deals to users via their phone.

UPDATE: the latest This Week In Asia podcast is dedicated to the growth of the internet in Indonesia. Comes highly recommended, listen here.