A month after its debut as a public company and eight years after its launch, LinkedIn in June 2011 passed Myspace to become the No. 2 social networking site in terms of visitors, according to comScore.

Marketers can gain perspective on how best to reach LinkedIn’s profession-focused networkers by analyzing how they use the site and where they interact. In July 2011, market research firm Lab42 surveyed LinkedIn users and found that the audience is highly engaged: 32% check the site several times a week and 35% check it daily.

Lab42 also found that 42% of users update their profiles regularly and 81% belong to at least one group. LinkedIn users are interacting with the site, which means they are also interacting with the companies on the site, as well as seeing the ads served there.

When it comes to the reasons why professionals use the site, employees act differently based on their position. Top level executives use the site mainly for industry networking (22%) and promoting their businesses (20%). Middle management professionals are more prone to use LinkedIn primarily to keep in touch (24%) with others, as well as for industry networking (20%). Entry level employees, not surprisingly, are using the site mainly for job searching (24%) and co-worker networking (23%).

Usage differences among demographic types are important for marketers to note, particularly if they are trying to target higher level executives or entry level employees with their outreach on the site. Advertising on LinkedIn, which can already be targeted based on education, location, job level and more, can be focused in various sections of the website, including jobs, groups or question and answers.

LinkedIn also has an unpaid marketing element to it, allowing companies to connect with interested parties via groups or answers. Now that LinkedIn is public, no doubt more information will surface about the site and how consumers use it, providing deeper insights for the marketing industry.