The group I am primarily trying to market to is teenagers, thus my use of Facebook advertising. I do have friends and family using the service, but viral growth

The group I am primarily trying to market to is teenagers, thus my use of Facebook advertising. I do have friends and family using the service, but viral growth is limited, as it is most useful among a small group of friends. I recently did change the ads and the landing page to be more teen-friendly, which increased conversion a bit, but still not to an acceptable level.