According to this article from Ragan.com, some companies have scrapped their web sites (or not developed them in the first place) to rely solely on Facebook to serve as their web presence. To me, that sounds like a terrible idea for several reasons and as I recall someone, somewhere saying: "Don’t build your house on rented land." (OK, it was something to that effect — don’t remember it verbatim. I’m not a parrot.) Since it’s the side I agree with, here’s the "Cons" portion of the argument. However, read the entire article and see if you agree:
Even with cost and ease in mind, ditching a company website and relying entirely on Facebook is “a bad idea,” says social media and Internet marketing consultant Anthony Kirlew.
“It puts the business completely in the hands of Facebook,” he says. “If Facebook changes, they are now subject to their rules. If they break some rule and their content goes away, they generally would not have a backup like a website that could quickly be uploaded to a new hosting provider.”
Philippa Gamse, social media strategy consultant and author of “42 Rules for a Web Presence that Wins,” agreed. “I have an example in my book of a small business which was banned from Facebook for seven months after building a nice following,” she says. “The owner thinks it was because a competitor reported him as abusive. Whatever the truth of this, you can’t call Facebook and get things resolved, and they don’t ask for proof of any abuse reports.”
By contrast, she adds, “Only you can take down your website.”
Gamse says companies that sell things online should probably keep their websites, because research shows people don’t go to Facebook to make big buying decisions.
Although many people visit Facebook daily, Kirlew stresses that not everyone goes there. “There are plenty of people who are not on and never will be on Facebook,” he says. “This includes executives and other professionals who simply don’t have the inclination toward it.”
Even executives who have Facebook presences may never see your messages, Kirlew says, because they have staffers who manage those pages for them.
Ever since I stepped into the now, so to speak, and got a smartphone, I’ve been much more aware of the need for businesses to have mobile web sites. Even when I’m at home — why not use my Blackberry when my computer is all the way in the other room? (Some call it lazy; I call it resourceful.) At any rate, 
If you’re like us at the Chamber, you took rebuilding your web site very seriously. We assembled a team of enthusiastic, in-the-know folks from various departments, each of whom offered what they wanted to see on our new (as of 2008)