I know myspace works great for a lot of up-and-coming bands, but I still think there are a lot of kinks to be worked out before it is an effective medium for more established acts to utilize.
The whole 'friends' thing is stupid. There is no investment in becoming a 'friend' on myspace, yet some people (and bands)are convinced that having a lot of 'friends' adds value to their popularity. But if there are, lets say, 10 million people on myspace, there is nothing to keep them all from accumulating 10 million 'friends.' In which case, they all may as well have zero friends. Yet, these 'friends' are not necessarily investing any more than a few seconds in adding you to their list -- usually to enhance their popularity, not yours.
I'm not saying that myspace shoudn't be taken advantage of, I just think that it has some pointless, novel qualities which will subside in the coming months as it evolves.