It's an age old debate at this point and folks have differing opinions depending on their situation. Web developers might be inclined to immediately defend their continued employment backing the need for websites; architects of the growing social media community might try to convince you otherwise. However at the end of the day, what's the deal? Has the time come to embrace services such as Facebook and do away with our own self managed online presences?
The pro-having-your-own-website argument:
Facebook is not yours. We only have access to it. Some believe it is dangerous to create a business on something that can change without your permission from one day to the next. Not only can a company such as Facebook simply change it's mind and restructure it's products (or remove them completely) on a whim (something it has already done with Pages), but the company could go belly up and leave you stranded after all your hard work investing time and effort into making the Page your online business presence. Also, there is no guarantee that Facebook won't adopt a policy of making users pay for the service at some point in the future. The current situation with Facebook's initial public offering doesn't really instill any more confidence either.
Of course the retort to that might be - how many companies out there base a large chunk of their services on Google products and services - the same problem would apply to them. The reality is on this one that you probably have a greater chance of being hit by a car tomorrow than Google or Facebook disappearing any time soon. It's not really possible to plan forever - we do what we can to survive for the forseeable future and roll with it for now.
A few years back, some companies thought it would be a great idea to only have a MySpace page and look what happened there so the reality is, there's no such thing as a free lunch. And of course more recently there has been a lot of talk of Facebook e-Commerce or F-Commerce as it is called. Chris Dixon, CEO of Hunch, said it best a while ago on Twitter: "Facebook is like Starbucks where everyone hangs out but no one ever buys anything." Even with the concept of implementing F-Commerce you still need an eCom backend somewhere else offsite, whether it is a third party company or your own site. So the idea that Facebook can replace a website currently definitely has it's limits - sure a Facebook Page might be able to replace SOME functionality of a website, but try adding anything more than a brief bio and a phone number and things get a little trickier.
Most companies realize that no one tool is the be all and end all to their marketing startegy. They realize it takes many musicians to create an orchestra. Effective marketing strategies often include many different elements - blogs, forums, user editable page content, informational forms, eCommerce, galleries, newsletters, databases and user logins to name but a few. A typical website can host and maintain most of these things under one branded roof. A Facebook page doesn't come close in this regard.
Even if you do decide to use a Facebook Page but decide perhaps to use nice template design to better brand your Page - the question then becomes, if you go that far why not simply build your own website? Where do you draw the line? Even the most basic site content is not easy to add on a Facebook page. Sure you can create an app for that but A) you will still need third party server hosting somewhere anyway to host app content and B) try creating a Facebook app to do something as simple as listing your about us info compared to using a self editable Wordpress CMS. Creating apps or extra pages requires skills beyond the average person where CMS makes adding new pages easy.
But is there a market for a Facebook Page? The answer is yes - if you ONLY need to post images, a phone number and some very basic info yes certainly. A Facebook page is in fact potentially a good basic entry level solution - after all the primary reason to be on the web at all is to increase leads and actively market yourself. If you have $0 in your budget for marketing then Facebook is as good a place to start as any and then when you have a few more dollars in your back pocket to apply to marketing you can rethink your options.
Some of the primary reasons for creating your own website over using a Facebook Page or equivalent include:
Branding - Facebook is fairly limited in that for the most part all you can do is add one giant banner image and a few pictures here and there. To be fair some might argue that really that's all you need - a logo and a picture with your number on it however.
Search Engine Optimization - You are more limited in terms of SEO on Facebook. Although Google might be inclined to trust and rank the likes of Facebook over some unknown, hidden website, content is still king and as such a website gives you all the expansion room you need to flesh out a large, juicey site, rich in content and useful information, something the search engines crave.
HTML v apps - Lets face it, creating apps in Facebook is considerably more tedious than creating content in a flexible CMS, and you do need some programming knowledge to do so.
Exposure - If you post content on Facebook there is a limited window of time in the river of posts that folks can spot your post. If you want to ALSO re-post from there this same content somewhere else (Twitter, Pinterest, LinkedIn) then ... well, you really can't.
... to be continued.