It's pretty simple, just grab the embed code for any video (YouTube, Vimeo, etc.) from the site where it's hosted. In Marketo, drag a custom HTML element onto your landing page, and drop the embed code there. You can simply change the javascript for the embed if you need to resize the video.
![0EM50000000SbKT.jpg 0EM50000000SbKT.jpg](/t5/image/serverpage/image-id/174i40913FB51FA2EAD6/image-size/large?v=v2&px=999)