It may be a gross simplification, but Facebook basically makes money by showing advertisements on Facebook, and by charging for transactions that take place within it. Facebook has been trying to commodify more interactions within its landscape, for example, sending messages, or making a post more visible. In short, it is in the interest of Facebook to keep visitors within its walls. Hence the importance of daily and monthly active users: the more people come, stay longer, and do more things in Facebook, the more opportunities for it to make money.
While Facebook campaign may be useful for brand awareness and reaching out to customers, as well as engaging with them, it is not a commercial platform where businesses can readily and easily sell their products and services: transactions usually take place on their sites, i.e. outside Facebook. And this is the fundamental divergence of interests: Facebook needs to keep people inside Facebook to make money, businesses need people to go outside of Facebook, i.e. their own sites, to make money.
In that respect, all those businesses and organizations pointing their actual and potential customers to Facebook, rather than their own sites, in advertising campaigns on television seems a little odd to me. It seems a strange situation, where businesses are doing a favour to Facebook by sending more traffic to Facebook, sometimes with incentives like free samples, from which Facebook is more likely to benefit than the businesses. Also, as I only keep a skeletal Facebook account, I lose interest when companies tell people to follow or go to their Facebook pages to see or learn more, when I might have looked up their actual websites if they had mentioned them. I probably belong to a minority, but companies asking people to go to their Facebook pages rather than their own sites alienate me, and that may represent a lost opportunity for businesses: many people are on Facebook, but that is not everyone who is on the internet.
There is no doubt that Facebook can be useful in connecting and interacting with customers and creating brand awareness, and businesses should have good social media strategies. Facebook could be a very good vehicle for word-of-mouth recommendations, and it may be possible to tap into a vast layer of potential customers. However I am of the opinion that Facebook pages – or any other similar online media such as Twitter or Google+ – should not replace or supplant their own presences on the web.