[2_3_billion]

I'd hazard a guess that, considering there's no real bar to clear for generating facebook content (an email address, maybe a prepaid phone number, and a working internet connection), it might be less than one in ten records is not the work of a business or automation outfit. So less than 10%.

Consider that algorithmic trading in stock markets is insanely noisy, and each trade comes with a fee. Many trades are executed as pricing probes, or efforts to exploit a minute shift in a given price. Assume facebook traffic has similar motives, just to suck impressions into a viral current for any particular campaign of appeal, or at least convince clientelle that advertising with a PR firm actually works. Gaining available eyeballs results in fractions of a penny in certain "users" pockets.