You mention the Pay-per-click campaigns, which I think are pretty interesting in their own right.. I just released a new demo, which is what I focused on and the average cost for a very targeted click through was ~$0.55, from my estimates about 50% of the people actually listened to the linked soundcloud track pushing the cost per listener closer to $1.10, but with the residual benefit that about 40% of the clicks also resulted in someone becoming a fan (or a liker).. There is also added bonus of the non-click impressions hitting a large number of people which adds to future name recognition. Compared to handing out physical CDs (roughly ~$0.86 per + time) I think it comes pretty close in value, but I have no solid data on how many people listen to the physical ones I hand out. Both would have side benefits.. but it’s interesting.

Also, http://www.rootmusic.com has done a pretty good job at making an app that has the bulk of the benefits that a myspace page would have, with inline soundcloud and artistdata (event info) feeds. The free version is pretty good on its own, the only drawback being facebook sends existing fans to the wall instead of a custom page. Hopefully that’s something that will change eventually.

http://djmarketing101.com/2009/09/02/something-from-nothing-8-steps-to-creating-a-scene/

You don’t have to book a big name to make things happen but it does help. However there are a lot of financial risks with that so be careful and good luck!