A visitor who watches is a visitor who stays.
Search engines can see that.
Most people do not read. Your customers skim a page, decide in a moment whether it is worth
the time, and go back to the results. Put a video on that same page and your customers stop
and watch it through instead.
That difference has a name. Dwell time is how long somebody stays before returning to search,
and it is one of the ways Google works out whether a page actually answered the question it
ranked for. A video is the most reliable way to move it, because watching is the one thing your
customers will do without being asked twice.
The video earns the page its position a second way as well. A transcript, captions and proper
markup mean every word spoken in it is indexed like the rest of your content, so one
production both holds your customers and gives search something more to read.