LinkedIn is a social networking site primarily serving as a place for individuals to post their resumes and CVs in order to network with other professionals in their field. LinkedIn was founded by Reid Hoffman, Allen Blue, Konstantin Guericke, Eric Ly, and Jean-Luc Vaillant in 2002. The company operates out of Sunnyvale, CA, and has offices worldwide. They are a subsidiary of Microsoft. LinkedIn makes the majority of its profit from selling user data to recruiters and sales professionals, advertising, and premium subscriptions.

Users can invite others to link their profiles to one another to publicly display affiliation. Additionally, LinkedIn offers access to job postings, professional articles, company profiles, and recruiters. LinkedIn has 630 million registered users in 200 countries. Alexa Internet reports LinkedIn as the 28th most popular website on the internet. Users must register to use LinkedIn services.

LinkedIn offers four types of premium subscriptions: Careers, Business, Sales, and Hiring. Premium Careers offers an application insight service, on-demand learning, access to a list of who has viewed your profile, and access to InMail. Premium Business offers access to InMail, profile insight services, unlimited profile browsing, and a list of people who have viewed the business profile. LinkedIn offers bulk discounts for the purchase of 30 or more subscriptions. As of this time of writing, subscription costs are $29.99 a month for Careers, $59.99 a month for Business, $79.99 a month for Sales, and $119.95 a month for Hiring. All four tiers offer a one month free trial to qualifying users.