First, it is necessary to explain what CM is. Actually, CM is the abbreviation of commercial message, which literally means advertisement. Of course, the concept of advertisement here is relatively broad. It can be a common commercial advertisement or various types of advertisements in other categories. For example, some music singles will play a promotional CM on TV before their release, which can also be called a type of advertisement.
CMizer is a service originating from Japan where users can create their own CM videos by simply clicking the mouse. As for the content and themes, there are not many restrictions; you can even use it to promote your own website as long as it's legal. The completed CM can be embedded into a blog.