The main reason why leading world companies create accounts in social networks is to attract traffic to landing pages and websites. YouTube's video hosting by the number of search queries is second only to the Google search engine, and you can attract some of this huge traffic flow to your site / landing page by simply posting your video (and related links to your web resources) on this hosting.
The reason I started Apache Leads way back in 2003 was that I was a Diamond level distributor for a San Diego based MLM company and had quite a large business. None of my associates had any access to leads, so that's how we got started. The demand for leads grew so fast that I had to focus on getting quality, affordable leads in ever increasing numbers.