1. People Will Look for You Online
Sooner or later, someone's going to type your name into a search engine. What do you want them to find? Nothing? These are people who want to find you, and if you don't have a website then you're letting them down - they expect you to be online. For many people, you might as well not exist if you can't be found with a search engine. Not having a website is like not bothering to get listed in the phone book. Whether it's customers or old school friends you're hoping for, very few people are going to find you if you aren't online.
2. Websites Cost Next to Nothing
Once, it cost a lot to run a website - but those days are long gone. There are 'pay as you go' services out there now charging as little as $1 per gigabyte of bandwidth. If you're sensible about the size of your pages, that dollar could last you a whole month, or even longer! If you don't want to pay for design, it's never been simpler to do it yourself, or find free software to do it for you. Really, it's never been cheaper to have a website than it is today.
3. Websites are great advertising
Whatever you're advertising - your services, your products, or just yourself - a website is a great way to do it. Every other kind of advertising going costs a premium, especially if you want to target a specific kind of person, and there's no guarantee that they're paying attention. Web sites are like brochures that are free to reproduce, interactive, and quickly distributed to people who are already looking for them. No advertising medium even comes close to the ease-of-use and effectiveness of a website.
4. A Website is a Worldwide Presence
On the web, it doesn't matter whether someone is next door to you or on the other side of the world - they can see your website just the same as anyone else can, at no extra cost to you or to them. Phone and post both cost enormous amounts long-distance, but a website lets you send information anywhere without any extra effort or expense. You can make friends and contacts in places you've never been and will never go - suddenly, working globally is no more effort than working locally.
5. A website can make you money
There's a lot of money on the web, and it's not hard to get some - the longer you're online for, the bigger your share can get. If you have something to sell, you can sell it worldwide, thanks to credit cards. Doing business online eliminates almost every overhead there is: all you need to do is have the goods. If you've written something useful, you can put it out there with a few ads. You won't get rich overnight, but you can set up a steady trickle of income... and there's no limit to the number of trickles you can set up.
6. A website can save you time
Giving out information takes time, whether it's on the phone, or in brochures, or even if it's just emailing your family. Web sites are designed to save you time. All your family and friends can read your online diary (known as a weblog), but you only had to write it once. Customers can see your whole product catalogue without ever needing to talk to you or visit you. This is the power of the web: things on it are written only once, but can be downloaded endlessly - a good website runs itself, and keeps being useful to people for much longer than you'd expect.