Retweet/repost is a part of your first bullet point, and is big in itself. There is a book about the history and present of social media from a few years back t

Retweet/repost is a part of your first bullet point, and is big in itself. There is a book about the history and present of social media from a few years back that calls out the retweet function as a major clshift in the viral nature of social media and its use to spread (mis) information.