From Facebook to Twitter to You Tube, there’s no limit to the number of social networking sites that can be leveraged to interact with customers and prospects, and build positive brand awareness. In order to expand your network, LinkedIn marketing efforts – like anything else – must be promoted in other channels. Include a link to your profile on your website and blog, in individual blog posts, in email signatures and even on business cards. Be sure to optimize your profile for important and relevant keywords. Allow enough of your profile to be public so search engines can rank that content accordingly.
http://www.toprankblog.com/2010/03/linkedin-marketing-tips/