Companies see social media as a big way to promote their &quot;brand.&quot; They are afraid of something going viral and hurting this brand, like the video of the AA attendant earlier this week, so they spend money to monitor their social media presence. Twitter has some hefty restrictions on their public API, but provides a private &quot;firehose&quot; that serves all Tweets. Companies pay Twitter, or Twitter&#x27;s partners,  a fair amount for access to this API. This is a major reason Twitter is still relevant. It&#x27;s essentially a public customer service line, where anyone can listen in. Imagine if you go to a website, and listen in on anyone&#x27;s call to Comcast.<p>Twitter is not the many to many graph that people envisioned it would be. Instead it is one to many. Either many &quot;ists&quot; talking to followers, or many customers complaining to companies. Twitter will be kept alive by its publishers, not its subscribers.