This completely depends on the Social Network you want to submit content to. Many social networks appreciate user-posted content and value the content that is created by the users themselves, but there are some social media platforms, For Example Digg, where most of the users do not appreciate the content that is owned by the users themselves. Such platforms only value content if it is authoritative or is a great share. So it is better to understand the demographic of a social network and their likes and dislikes before posting your own content.