I don't work for one, but I'm aware of several "closed door" pharmacies like this. I actually get recruited about every 1-2 months for jobs in these places.
Some retail locations will do this in a small way, but they are ususally larger corporate pharmacies (Kindred, etc) who specialize in this business.
Just my personal opinion - its boring work (& since there is lots of turnover, others must think so as well). You check tech dispensing, do once a month chart reviews, track controlled drugs - ugh....!
But - there's a place for everyone - and yes, they do charge a fee for this service. Chart reviews are required by law here, so that is a separate billable fee. You can tack on an extra dispensing fee for the individual units of use, so the $$ of 30 days of medication is a bit higher in these places than in others. But - they've got you caught. If you're a pt in a SNF that has a tight agreement with a "closed door" pharmacy, you can't get your rxs any place else. Some are more lenient than others, but it depends on the licensing, who is giving the medication, etc...