Overview
Marketo allows playback of certain videos in their emails that are sent out. There is a restriction here
Solution
http://docs.marketo.com/display/public/DOCS/Edit+Elements+in+an+Email#EditElementsinanEmail-HowtoEdittheVideoElement
Vidyard's player relies on the javascript that gets run so that we can get the analytics back to the platform. Marketo allows playback inline for youtube - as it just gets the view info. No additional information. Until Marketo allows embedding inline javascript into the email, we will not be able to play inline.
A work around for this is to have a link or thumbnail to the Vidyard Share page and have the playback occur on that page.