I assume so*, as long as that is as far as the advertising goes. PMing people for the purpose of advertising your "free items conga" is against the rules, however.
Forum Rules and Guidelines wrote:
Do Not Abuse the Personal Message System
Occasionally, and for various reasons, some members feel the need to start sending many identical personal messages. This normally occurs when a member joins simply to plug his/her own website. If you recieve such a PM, or any other sort which you think might break any of the forum rules, forward it to a Moderator.
*You'll have to get a staff member to fully clear things up.