Soundclick and myspace are oversaturated, but if you can promote it where you'll be recognized then great. You definitely would need it for exposure, so it can help you get your name out. I've seen plenty of people who have their own domains and they have their url forwarded to their myspace or soundclick, because the information is already there. Their myspace is usually customized anyway, so they're using their domain name properly. But really how many people go to the website already? I feel if you don't have a following already, it's difficult. You need everything, twitter, facebook, a blog, myspace(even though no one uses it except for musicians). You really have to promote, but I think having a domain name that forwards to your customize myspace or soundclick is a step in a right direction.