While there are several platforms for doing this, clearly YouTube is the most popular for doing this. However, video marketing is also a great form of both content marketing and SEO on its own. It can help to provide visibility for several different ventures, and if the video is valuable enough in its message and content, it will be shared and liked by droves, pushing up the authority of that video through the roof.
On April 24, 2012 many started to see that Google has started to penalize companies that are buying links for the purpose of passing off the rank. The Google Update was called Penguin. Since then, there have been several different Penguin/Panda updates rolled out by Google. SEM has, however, nothing to do with link buying and focuses on organic SEO and PPC management. As of October 20, 2014 Google has released three official revisions of their Penguin Update.
Digital marketing is defined by the use of numerous digital tactics and channels to connect with customers where they spend much of their time: online. From the website itself to a business's online branding assets -- digital advertising, email marketing, online brochures, and beyond -- there's a spectrum of tactics that fall under the umbrella of "digital marketing."