Recruiters are increasingly using social media sites - Facebook, Twitter and LinkedIn - to fill job vacancies.
LinkedIn, which is known as the "professional network", leads the way, but Twitter and Facebook are underused and are expected to make up ground over 2012, says US-based recruitment-platform provider Bullhorn Reach.
Bullhorn said LinkedIn was adopted much earlier for recruiting, which is why recruiters have smaller networks on Facebook and Twitter.
Bullhorn Reach provides specialist recruiting software that enables agency and corporate recruiters to better use social networking sites to find candidates for jobs.
Bullhorn said that recruiters were likely to increase their activity on social networking sites in 2012 as the world becomes even more connected through the big three social networks.
"Based on current data trends, recruiters could quadruple the size of their Twitter networks by the end of 2012 and potentially add approximately 1,000 connections to their LinkedIn networks," Bullhorn said in its 2012 Social Recruiting Activity Report, which was published on Wednesday.
"Currently, Facebook has the least amount of network activity among agency and corporate recruiters.
"One would anticipate them to alter their strategies, going forward, to leverage the power of the largest social network - for example, employee referral programs."
Bullhorn said it also expected that other social networks such as Google Plus would boost their efforts to grab a share of the recruiting space or develop strategies that attract certain segments of the professional population.
The Bullhorn report found that recruiters were connected to all three big social networks but were using LinkedIn and Twitter more than Facebook.
LinkedIn was generating more views per job than Twitter and Facebook, sending three times the amount of views of Twitter and six times the amount of Facebook.
Recruiters posting jobs on social networks were likely to receive more applications from LinkedIn than the other two networks.
LinkedIn generated almost nine times more applications than Facebook and three times more applications than Twitter.
Twenty one per cent of recruiters were connected to all three social networks but 48 per cent exclusively used LinkedIn, which has 135 million active members who used the site to search for jobs and manage their professional identities.
The findings were based on data from the Bullhorn Reach user network of more than 35,000 recruiters during the 2011 calendar year.