Exactly where did you get this “must have video” information?  Video is not necessary for any website. It’s nice to have but CANNOT replace words on a page. If you have an “about me” video without words on the page, how would that page be indexed by a search engine? The only way a video can replace words is if the video name, title and alt text contain all the words necessary to index the video. That might be too many words to be taken seriously.

Don’t buy into everything out there – 90% of it is nonsense. 

Video is nice but for a business website, don’t include automatic sound! For personal, yeah do whatever you want. 

Hi Dea – Video is a great enhancement tool. Don’t let it play automatically though. Let the user decide when to play the video, at their convenience. 

I would say “common sense” is the 10% but not everyone keeps up with all the search engine updates and foibles.  So, “internet common sense” only comes to those who work in the environment everyday for multiple venues online. It’s impossible to tell someone how to know the difference.  

This is where these groups of folks (social media clubs) can help by dispelling much of what you read, that may sound good in theory but not in actuality. Plus, what might work in one niche market can be taboo in another.  Experience is the key.  The best thing to do is ask people you trust.