Does Facebook Fan pages have long term value for client?

I'm trying to understand how people are selling Facebook Fan pages for local businesses. The ROI seems like it'd be so little, and aside from creating a Facebook ad campaign, is there even any other way to get real legit fans?

Can someone explain what services they're offering companies to be able to charge a monthly fee for their services? I can't see how businesses would even see the ROI on this model, so I'm curious.