But back in the days before the internet, people had to do other things to get the word out...
Here are a few suggestions for how you can expand your fanbase without getting RSI!
1. Take to the streets

Well, some of you might say this is stereotyping, but to that I say that stereotypes exist for a reason! If you write trance music and see someone in a Tiesto Tee walk past, chances are they're more likely to enjoy your tunes than the kid in the Slipknot hoodie. Approach people, play them some mp3 clips and tell them where your nearest show is.
If you leave them with a business card they can put straight in their pocket with your web details on, then you can continue the fan-artist relationship online when you log on upon returning home.
2. Go to Gigs
When possible, instead of going to the streets, find out where some big artists with a similar sound to you are playing, then hit the queues outside the venue.
Again, chat, make friends and don't forget to mention how awesome your latest tune is!
3. Networking events

There are several musical events around the country - go to them! Talk to everyone. Make fans out of the gear manufacturers and the website developers. Everyone there is passionate about music, so they're a really receptive audience!
It's also a great way to keep up to date with what's going on in the industry. As with all the methods, a great way to make new fans is to make friends! Friends help you out by coming to shows and buying music.
If enough friends do it, the fans will eventually follow - friends of friends are probably going to be the first wave of fans that you don't actually have in your address book!
4. Arrange flash-mobs
Here's one for the more adventurous of you - A Flash Mob is where you organise a bunch of people to do something unusual at an allotted time in a public place.

If you can organise your fans and friends to do something obscure to promote your tunes, not only will it make them feel more tied in to you as a musician, but it will no doubt raise awareness, so long as you leave the people thinking "Uh... What just happened?".
If you can also leave them with a business card explaining where they can find out what just happened, so much the better!
5. Contact local Radio
Local Radio stations are a great way to practice your interviewing technique and to get your tunes out to the people down the road without going door-to-door (though you could try that too - if it works for the Mormons it could work for you!)
Just give them a call and remember - make friends. I've previously had friends in local radio that have moved up to bigger and better things in more popular radio stations, taking their willingness to assist a local mate with them! Very handy.
I'm sure you can come up with plenty of other ideas, but here are 5 to get you started. So get out of the studio for a while, rest your eyes and build your social network!