The battle started when Facebook bought Instagram because it was better to be the competitor rather than compete with it. Then Twitter looked for a come-up and discovered Vine, which allows users to post six-second videos. 

People are calling Vine "the Instagram of video." The issue with that is Instagram is far too large an entity as a photo-sharing network to allow another brand to rival it. Otherwise, what exactly is Facebook's investment all about?

That's why Instagram is rolling out its own video-sharing program to keep up with the pace. 

From Jessica Guynn at the LA Times:

Facebook is playing catching up, trying to tap into the Internet's latest medium for self-expression.

Adding video will heighten competition for marketing dollars with Twitter. It's a direct swipe at Vine, the simple-to-use filmmaking tool that lets anyone create six-second videos that run on an endless loop.

Twitter bought Vine in October and debuted the video-sharing app in January. It has soared in popularity, grabbing the attention of teens, celebrities and brands that want to reach consumers on mobile devices.

In just four months after launching on Twitter, Vine racked up 13 million users who collectively share millions of videos each day, rivaling the swift rise of Instagram. Instagram took nearly a year to reach 10 million users. That's why many people have dubbed Vine the "Instagram for video."

This is a great thing for avid social media users. The more these entities slug it out for preeminent status, the more outlets that will become available.

It's also going to be interesting to see where we go from here in evolving the way we express ourselves.