In this day and age there are at least two or more computers in every household and business and usually they are networked together in some fashion or another. There is really no issues for home networks, but when it comes to small businesses, there is a certain point where you have to look at moving up to bigger and better things.

What I am talking about is a network server.

If you have a small business and you have less than 10 computers or devices, you are okay. On the borderline, but okay. If you go over 10, it is recommended that you look at going to a server based network. The reasoning behind this is you probably have an adhoc network setup. Meaning you have a DSL line or cable going into a modem, to a router, to a switch, to all your devices. You share folders, exchange data, and above all share the internet connection.

It works. But as you grow, and add more to your network, you get more PC's and devices, you could run into issues. If your business is growing and you go above 10 PC's and devices, moving to a server is advisable as it will open all sorts of doors for you.

A network server by definition is a computer designed to process requests and deliver data to other (client) computers over a local network or the Internet.  This includes (depending on the OS) a database, email exchange server, various other bells and whistles that can enhance a companies productivity.

There are all sorts of options you can do, but I recommend that if one can afford it, to buy your own server and that way, it is yours!
You can take it with you, move it wherever and you don't have to worry about hosting companies moving, going out of business or being bought out.
No one likes change.

This of course comes at a cost. Servers are not cheap, neither is the software. This includes an IT person to setup and maintain it.

A system, if setup and maintained properly requires very little and IT support cost is low. Twice a week to come in and give it the once over, check logs, update, etc is about it, unless the job entails more. (company dependant) IT support can cost (depending on the area/demographics) anywhere from $75.00 per hour to $225.00 dollars per hour (approx).
The variables are many and those emergency "I NEED YOU NOW" calls are on the higher end of the pricing spectrum.

If you feel like you would like to move to a server, ask your IT specialist for a quote.
How much would it cost to move to a server?
What are the benefits to the company?
What do you want the server to do for you?
Do I really need a server?

The information is out there all you have to do is ask.

All in all, it is what you the business owner feels comfortable with and can afford.
As an IT specialist, all we can do is show the options available to you.