When it comes to your participation in social media, are you spending most of your time on Facebook and Twitter? If so, you might be overlooking the marketing potential of a very important and valuable social network: LinkedIn .

According to Lab42's July 2011 survey of 500+ LinkedIn users , 61% of LinkedIn users said LinkedIn is the social site they use most for professional networking. Thirty-five percent also indicated they check the site daily. Now that's quite a bit of activity!

Furthermore, these LinkedIn users are also active in other social networks as well. Forty-six percent of those surveyed said they also have a Twitter account, and 79% indicated they have a Facebook account, too.

So how exactly are these people using LinkedIn?

The large majority (81%) of users surveyed belong to at least one LinkedIn group, and of those users, 52% participate in group discussions. Additionally, the study found that industry-specific groups are the most popular type, compared to employer-specific groups and groups of members based on educational connections.

The study also found that LinkedIn usage varied depending on users' professional level, though a key usage commonality across all levels was industry networking.

How Marketers Can Take Advantage of LinkedIn's Popularity

Lab42's data just goes to show that with LinkedIn's popularity among industry professionals, it behooves marketers to engage there, too. Here are a few great ways marketers can take advantage of LinkedIn's popularity for marketing.

1. Optimize Your Profile: The first step in taking full advantage of LinkedIn is to optimize your profile . A complete profile will offer a more credible presence and lead to better LinkedIn engagement.

2. Create an Industry LinkedIn Group: The fact that so many LinkedIn users are getting involved with groups should encourage you to create your own. Create the group around an important industry topic, not your company. Managing and maintaining an active LinkedIn group that provides value to its members is a great way to differentiate yourself as an industry expert.

3. Share Your Expertise in LinkedIn Answers: LinkedIn's Answers feature is an extremely valuable marketing tool. Users can ask questions, which can be searched by industry categories and topics. Marketers can take advantage of this feature by searching for questions in their industry and answering them when they have helpful information to offer. Marketers can also use the opportunity to link to their content such as blog articles, ebooks, webinars, etc. on the topic in question if it can provide added value, which can potentially aid in lead generation.

Are you taking advantage of the marketing opportunities offered by LinkedIn ?