d45f731d_Pages__and_5_That_Do____Gigaom__Benefits_to_You
[Reason] 3. They are doing it because someone they know asked them to do it as a favor. [Interactions on Page] Moderate to Low [Benefits to You] 
Not much, unless they are engaging at the behest of the person they know as a favor to the person they know and this mostly will just create some activity on your Page that others can see when they arrive.
5 Things That Don't Work on Facebook Pages (and 5 That Do) | Gigaom
Benefits to You