A very successful businessman once said that half the money he spent on advertising was wasted - if only he knew which half!
I think that you have to have your name out there as much as absolutely possible, covering every type of media available to you. On average it takes 7 points of contact before a sale is transacted. What that means to us is that some people will see your number on a flyer and call straightaway, others will see your number and think "I must phone her", but not get round to it for ages. Having a website is one weapon in your advertising armoury, and i think it's an essential tool these days. I also think that there are lots of people who actually don't use the internet like we do (it's easy to think that because we're all net savvie everyone else must be too!) and will still use Yellow Pages, Thomson Local, village directories, so having an ad in those publications can be useful too.
My website has brought me quite a bit of business. I change it regularly, have a mailing list and will be looking to allow online booking in the near future. I have a webshop and have sold several bits and pieces through it, and I rotate the products I sell on it to keep it fresh.
I used Freewebs, bought my own domain name and then upgraded to their pro package which costs me 50 quid a year. I used one of their templates and tweaked it a little bit, but it's honestly pretty easy to do. I change the wording and the images from time to time to reflect new treatments and seasonality.
I think you'd be missing a trick to not have a website. If you need help with one I'm happy to help, and Ruth Mills is an invaluable resource too!