The three types of online videos can be distinguished in many ones, one of them being where they are placed in relation to a company's website. Mostly videos are located on the site's homepage, within a specific page on the site, or embedded from a third party site such a YouTube, FunnyorDie and CollegeHumor.com. Strategically placing the different types of videos help a business achieve different goals.
If online video was launched with the creation of Youtube, viral video was the first "breakout star" of the medium. The definition of a viral video is "a video that become popular through the process of internet sharing, typical through websites and email". In order for a video to have a chance to become viral but must either original. unusual, unexpected, funny or mysterious. Viral videos are almost impossible to create because they must have that "buzz" that will inspire people to not only watch it but share it with their friends regardless of the content. Viral videos are usually placed on third party sites in order to generate traffic back to a company's home page. The aim for this type of video is to be embedded on many different sites to reach as many viewers as possible. The only downside to the distribution and promotion of this video is lack of control companies have over these videos. If they are put on websites that have surrounding text or ads that aren't inline with the company's image, the unsavory content could give your company logo a bad reputation even if it does increase the popularity of your video.
T-Mobile pulled off an extremely successful example of viral video with this pre-planned flash-mob at the Liverpool train station in London, England. It has received almost 15 million views on their official Youtube channel alone, have you seen it yet?
References: Sevitt, Daniel "Online Video for Business" ReelSEO. http://www.reelseo.com/types-online-video-business.