Steve....I was just looking at the TERMS on MySpace. Check this out:
Non-commercial Use by Members. The MySpace Services are for the personal use of Members only and may not be used in connection with any commercial endeavors except those that are specifically endorsed or approved by MySpace.com. Illegal and/or unauthorized use of the MySpace Services, including collecting usernames and/or email addresses of Members by electronic or other means for the purpose of sending unsolicited email or unauthorized framing of or linking to the MySpace Website is prohibited. Commercial advertisements, affiliate links, and other forms of solicitation may be removed from Member profiles without notice and may result in termination of Membership privileges. Appropriate legal action will be taken for any illegal or unauthorized use of the MySpace Services.
So....I think MySpace is out in that regard. You may want to see if you can advertise on MySpace. That may be an option. Here's a link to contact somebody regarding advertising:
MySpace
I hope that helps.