> If the video follows you down the page in a paused state, with thumbnail and "play" icon, would this be okay?
Absolutely not. If the video is useful content, put it front and center, and let the user hit "play" on it; if they scroll it away, accept that they don't want it. If it's unrelated content (as with the thousands of "news" sites that want to autoplay an unrelated "hey look at this completely unrelated garbage" video), put it under a "related stories" column or similar, and stop making it jump around the page to draw attention. The user is already on the page they wanted, their attention is exactly where they want it to be, and your job is to serve them what they want, not what you want.
"Engagement" might be easy to measure (hey look, if we pester the hell out of users we get a few more users who accidentally watched the video), but the much better metric for long-term sustainability is "how many users love your site and think 'this is awesome'".
Absolutely not. If the video is useful content, put it front and center, and let the user hit "play" on it; if they scroll it away, accept that they don't want it. If it's unrelated content (as with the thousands of "news" sites that want to autoplay an unrelated "hey look at this completely unrelated garbage" video), put it under a "related stories" column or similar, and stop making it jump around the page to draw attention. The user is already on the page they wanted, their attention is exactly where they want it to be, and your job is to serve them what they want, not what you want.
"Engagement" might be easy to measure (hey look, if we pester the hell out of users we get a few more users who accidentally watched the video), but the much better metric for long-term sustainability is "how many users love your site and think 'this is awesome'".