Online Australians are increasing their participation rate in social media at a rapid pace, with content sharing the most popular social media activity, according to a report from Nielsen.

The ‘2010 Social Media Report’ found that close to four in five Australian internet users (78%) sent or shared a photo in the past year and nearly three quarters (74%) sent or shared a link.

The biggest increases in social media usage were reading and posting on Twitter, reading wikis and engaging with brands and organisations via social media, including watching online video to support purchase decisions.

Twitter’s audience levels grew by more than 400% in 2009 and nearly one quarter of online Australians (23%) read ‘tweets’ in the past year, 14% ‘followed’ companies or organisations via Twitter (up from 5% in 2008) and 13% posted ‘tweets’ (up from 4% in 2008). Wikis continued to grow as a popular form of online content – close to three quarters of Australian internet users (73%) read a wiki in the past year compared to 61% in 2008 and just 37% in 2007.

Melanie Ingrey, research director for Nielsen’s online business, indicates that nearly nine in 10 Australian internet users (86%) are looking to fellow users for opinions and information about products, services and brands.

“Australians’ engagement with online word of mouth communication is going to increase in coming years as social media plays an increasingly important role in consumer decision making. For now, the battle of the social networking sites has clearly been won, and Facebook has proven its dominance by providing valuable and compelling content that has users spending more than eight hours a month on the site,” said Ingrey.

Social networking on sites such as Facebook was a key driver in Australians’ trial and uptake of social media. Close to three in four online Australians (73%) have looked at others’ profiles on social networks and well over one third (37%) of these report to be interacting with others via social networking sites on a daily basis.

Facebook dominates the online social networking space, with three quarters of Australian internet users (75%) reporting to have visited Facebook, 59% have a Facebook profile and the average time spent on Facebook in a given month is eight hours – seven and a half hours more than its closest rival site, YouTube.

Moreover, 83% of social networkers name Facebook as their main social networking platform, up from 72% in 2008 and 34% in 2007.

Nielsen’s report found that over one quarter of social networkers (26%) participated in mobile social networking in the past year, with younger consumers the most likely to participate in social networking via mobile – 66% of mobile social networkers are under 35 years.

Facebook is the most popular social networking site accessed via mobile (92% of mobile social networkers have visited Facebook), followed by YouTube and Twitter (18%) and MySpace (9%).

However, Twitter sees the most frequent mobile usage, with half of its mobile users visiting the site daily. In comparison, Facebook saw 36% of its mobile users visit the site daily, while 22% of MySpace users and 16% of YouTube users were making daily visits.