When I had my web design company I had a lot of work for presenting the offline companies through a web site.

It was just their digital business card.

Introduction, explanation of services/products and detailed contact information and contact form.

Sometimes even support through a forum like vbulletin.

Most companies have a site so they can promote their business on the internet too.
But the updates are slower, a lot slower.

But would that "online business card" thing actually work? How could it be promoted in the search enginges with so little content?

it is the other way around, users go from offline to online to check the url and find out more about the company after which they hopefully purchase.
the search engine entries are just an extra.

Ahh, I see ... here is why I am asking. My family owns a family-run optical store (we sell glasses). My mom keeps trying to get me to set up a webpage for the store. She thinks that me buying a domain name to put an .html page on it with our company name, address, and phone number is somehow going to increase business by soooo much because we'll have an online presence.

I just keep trying to tell her she doesn't understand the internet

It depends how you do it
The opti sites that I noticed in our country get 25% more customers by having a dynamic online presence.

Perhaps putting all inventory online? Hmm ... it seems more work than it's worth though.

You could just create a simple online page and have it as extra contact point

a phone
a fax
an email
a web site

go with the flow

In a way she's right....but only if you advertise and register the right way.

I used to help run www.southernshares.com (now has been taken over and dismantled) and their technical presence. For the most part, we were a front end to a commercial/residential construction company. Now the commercial is what I was concerned about. We took small companies in Ellijay, GA and gave them an online presence. Most people think this is going to increase sales...and it did in some instances. However, unless you have the capability to provide services across state lines, then you shouldn't expect an increase in sales/profits.

What we told our clients we would provide is a page that EXISTING customers could use to enhance their products/services they had. For instance, we had a dance club that was built by southershares that we put up a page for. This was especially good for the grand opening because the page had a webcam that documented the construction process and told about the vision of the owner. When his investors wanted a look at what was going on...they just had to type in the url. It was great!

After the club was built, we provided a year of service to the owner for a discounted price due to him going with us for construction. His online presence most likely didn't make the masses want to storm his front door...but it did give him the impression that he was professional and 'in with the times'

For your parents, I think having a webpage couldn't hurt a thing and might even get the word out for them. But you'll have to explain that if they want sales to increase, they have to be willing to go at least USA-wide and be willing to compete with discount prices already available on the internet.

Another problem is that your pricing online and offline have to agree within a few percentage points. So you can't quote a huge discount across the board online and expect your local customers to continue to pay higher prices. There are a bunch of things we could go on and on about. Bottom line, a website = good image, but won't = big business unless
a) willing to go international
b) it is done right
c) willing to compete with other online websites
d) prices agree across the board

My 1.2 cents worth.

Well the problem is that this is a small family run optical store. Where people come in, browse through our available selection of glasses, try them on, and pick out which one they want. Then they get an eye exam with us. Then they come back when the glasses are ready for a fitting.