Does EVERY business need a website, no.  Would 99% benefit from having an online presence, I believe YES.  When Matt and the Local University came to Mineapolis, they gave a great example of how a local taco stand (i believe?) received an increase in sales just by creating a google local page.  No website, but still an online presence.

Now does SEO offer value to every business?  Thats a more intriguing question to me.

I say not every business needs one, and due to the popularity of Facebook and local portals I don't think this will change any time soon. However, I do confess that when I am looking something up, like a new restaurant or store nearby, if they only have a Facebook page and no real website, it annoys me and I think a bit less of them. I imagine that depending upon your niche, you could easily get away without a proper website. I don't have to like it though haha!

Yes, I believe so.  You need someplace to call Home online.  A place to send friends, colleagues, clients/customers that you can truly call your own.  Someplace to link to when the opportunity arises, someplace to verbally pass around when you run our of business cards.  Someplace to list on your business card, menu or brochure.  You need an environment for your brand online that you can control the messaging to balance your ORM from places like Yelp, Rip Off Report and raving/ranting blog posts.  You need this web home to also be where you link to and from your Facebook, LinkedIn, Twitter, Blog, and other online accounts, profiles and pages.  You need a website for mobile phone web surfers because this large and growing segment absolutely DOES NOT USE THE YELLOWPAGES ANYMORE.

You also need a website to help you just plane generate more leads and sales from this interweb thing that you keep hearing your friends and kids taking about getting on.

The simple answer is definitely YES. The question might be a little off, though.

If you want people to be able to find your business when they are looking for it, you need a website to be part of that answer. It doesn't have to be a full-fledged site, but you need something personalized and branded on the internet with your business' info on it. Search engines need to be able to find it and index it. And you need to make sure the info is current. This can be as simple as making a "site" that is no more than an online business card.

The fact of the matter is, however, that you'll be missing some opportunities if you don't have a site. For the low cost of entry, it should be considered an essential part of any business.

I think all businesses should have a website.  However, many businesses could get by with accurate Google / Bing places pages so long as they are up to date and fleshed out with the sorts of information that a prospective customer would want to know.  However, businesses without websites are definitely at a competitive disadvantage and it's better to have an unoptimized website instead of no website at all.

A few years ago, I wrote an article arguing that there were plenty of small businesses that didn't need a website. Now, however, I'd have to disagree with that opinion because I think virtually all do.

People are 'finding' what they need online in many different ways and many different places, so it's important to try to be 'where they are' as much as possible. For many SMBs, that still means their potential customers are starting with search.

Yes, you might be able to get your Facebook Fan Page to rank, but what happens when Facebook changes the rules? You might just disappear from the SERPs altogether.

And, while I'm a big believer that local search should be one of the tactics most SMBs implement, that's still too fraught with problems for me to trust in it 100% as my only online presence.

Having your own website as the hub for other places your business is online seems the best short- and long-term strategy to me.

I absolutely believe you need a site if you are a business. It doesn't need to be fancy or more than a few pages, but you need to have a homebase to operate out of. Relying 100% on a 3rd party for your presence is irresponsible.

What happens if your competitor hires a bunch of kids to graffiti your reviews on Google Places, Yelp, etc.? You think a 3rd party site is going to immediately respond to your little taco stand's request? Good luck.

It's so easy to set up a quick site. Wordpress and go. Now you can manage your online reputation! Wow. And for free! With IMMEDIATE control over everything.

I have to vehemently disagree with the folks in this post recommending anything different. The kids growing up now don't know what a "yellow pages" is. Are you going to trust Google to represent your presence? #EpicFail

Who is recommending anything different? Todd and I both said you could probably get away with it. Neither of us think it's a good idea though.

I was discussing this with my barber the other day (just one guy in a single rented shop). In the end we agreed that he should just use Facebook and Google Places but he should also buy a domain to use for email. He can reach out to existing customers via Facebook and get his shop found via local searches.

He didn't have the time or money to spend building and ranking a website but owning a domain would allow for consistent branding and mean he could salvage something if/when FB jumps the shark.

Yes... hands down. It is so annoying when searching for a small business or local business by name and you can't find them. In most cases, a basic HTML home page with contact information would be enough... as in the "Barber" example above.

Ditto to Karl.  It doesn't have to be much but I think it shows that the company a) understands the importance of the web and our reliability on it; b) provides visibility online and opportunities for new business that may not have been found otherwise; and c) an easy place for people to find vital information (phone number, address, etc.)