netmeg - 6:05 pm on Mar 16, 2012 (gmt 0)
I suspect it's none of those things by themselves.
Are you doing what you do better than anyone else, and is it obvious? That's probably what they mean.
So you gotta be unique.
You gotta engage.
You gotta provide value.
You gotta have a Google+ page (ok that's not a quality signal to *us* but apparently it's one to Google right now)
You gotta appear to have some measure of trust and authority.
The laundry list (checklist) of this this this this and that doesn't work anymore. You have to look at your site as a whole, and ask yourself, if you were a user of this site, would you recommend it to your mom? would you bookmark it? share it? buy from it? Are you immediately discernible from 100 or 1000 other sites that might be doing the exact same thing?