Just to clarify I'm not a marketer, in SEO or any form of webdesign, just in case that was being suggested. There are countless examples of companies not in these industries using FB ads successfully, as I posted in the article earlier (check first post I make), Unilever one of the biggest FMCG companies in the world has had a very good ROI. Some start-up/small businesses too have hit Facebook ads hard and done well as a result, for example 'ShiteShirts'. Pretty much all businesses can benefit from social media outlets no matter the size because for one thing they are free, so we can't effectively use the term ROI (unless we're relating time to financial value and in this case its still a good ROI, the time to get new clients through social media can be a lot quicker than other methods).
The fact remains that a well thought out, free FB fanpage is clearly an asset, ask any company who has a large fanpage. Ultimately the problem in my opinion of companies that complain that their fanpage is 'not working' often (not always) lies on getting the right type of fans in the first place... www[dot]socialmediaexaminer[dot]com had a few interesting articles that I read a while back on the topic of organic fan growth to drive sales of whatever product or service.