Is there a workaround to display Ad Network video content triggered by Unity?

I've been looking around a lot and found that it is not possible to display video or image content from ad networks like AdSense because Unity cannot display HTML content. Is there a workaround? For example: Is it possible to have a mid-roll video ad play by hiding the Unity web player, displaying the content on the website itself behind the hidden web player, then restoring the visibility of the Unity Web Player again?

Thanks in advance.