Facebook allows you to search for jobs within a particular industry. When you create a job application, the document will be filled directly by your work history that is on your Facebook profile. This feature is similar to the resume feature in LinkedIn.
Facebook seems to be serious about developing business related programs and products. Since 2011, they have spent US $ 1 billion for the business.
Primarily, they are interested in working with small to medium sized businesses, which have an important role in the Facebook advertising business.
With more than 2 billion users, Facebook has room to grow. However, so does LinkedIn, which now has 500 million users. It's possible that Facebook is targeting different types of users from LinkedIn. If LinkedIn gives a professional impression, Facebook is casual.