Speaking of Facebook ... I'm interested in knowing if "experienced" microstockers use Facebook to steer buyers to their images?  For instance, could I use Facebook to promote my current editorial images of sporting events.  Would editors/buyers find my work in a google search if it was advertised/promoted on Facebook?

Am I making any sense at all?

I think we need to wait before tearing these sites apart. Some could be little more than personal portfolio sites for a few photogs that have banded together and tried to make it all look a bit more professional.
I mean they might not be trying to take on the big boys, just trying to shift their own work.
I know I have joined a couple of little gem sites that make me more then say bigstockphoto by selling at midstock prices. They have a limited customer base, but also nowhere near as many contibutors, sometimes just a handful, so you get a bigger slice of the small pie.