This doesn't mean I'm anti-Twitter or Facebook or whatever.
As Gerry covers here, people engage with you because they want to do something. Not because they want to watch a video or download a PDF or 'Like' you.
Nobody is interested in documentation, tools, videos, blogs or Twitter for their own sake. Their interest in these things is only in the context of the task they need to complete.
The format is not the task - article by Gerry McGovern