I have to say that the term "lurkers" to describe the 90% who don't participate rubs me a little the wrong way. I know this point is somewhat trivial, but it has a negative connotation that seems to promote the assumption that the only "correct" way to use social media is for all to participate.

On the flip side, I wonder if everyone on social media were to comment on most items they had interest in, if it wouldn't completely drown out all of the extreme viewpoints. It may actually make social media extremely boring, as compared to the current standard. One can dream...