I think a combination of channels needs to be used to generate a following. The problem for me, like I mentioned in a previous post, I have to promote a metal band but I don't know where to find the metal heads (target market).
If someone walked into a room and handed out flyers for a metal gig chances are that they would not even bother to give me one, coz I'm disguised as a yuppie but in actual fact a die-hard metal fan beneath the surface. It’s not like ppl walk around with a label "metal head" on their forehead. As also mentioned in said post, the metal heads aren't at the metal gigs... they are scattered all over the place. Step 1 is thus to identify the best place to reach your target market - this will most likely be the most difficult and time consuming part, and is something that can only be generated over time.
Secondly, I believe one has to apply a Direct Marketing approach in order to promote an artist or group - this entails creating a database of potential fans / target audience and continually communicating with them and forming a "relationship". I'm not talking about a mailing list where you're just spamming them with info, it goes far beyond that - If you're serious about it you need to personalise the communication.
http://en.wikipedia.org/wiki/Direct_marketing.
The more you know about your target, the better you can customise your message.
For example, there's a major difference between:
Example 1) "Hi there, band X jamming at Venue Y on such and such date - please check us out"
Example 2) "Hi John, we know that you like to have a cold <insert his favourite brand of beer> and chill with great friends like <insert names of his friends>. Why not grab a few buds and come check out band X at <insert favorite venue> jamming with <Insert some of his favourite local acts> on such and such date..."
The 2nd approach is much more likely to lead to a response me thinks...
Finally, keep them interested by sharing band news, photos, demos, t-shirts and even asking for their inputs and opinions to your music.