I use it regularly. My business is across the street from a university. Those kids are wired up 24/7. I use it to run promos and link it to my website. I use as another link in my advertising message. It enables me to run specials quickly, or tell people the soup of the day etc. I use it to reach the under 30 crowd. They don't read newspapers, listen to the radio, or look for direct mail coupons. Which were the primary weapons in my advertising arsenal. I guess still are, because there is a segment of society that does read the paper, listen to local radio, and clip coupons. And there money is just as green as the under 30's. And they have more of it.
I mainly "follow" local folks who can impact my business, or have something worth saying..
Most of the stuff on there is just narcissistic bullshit.