One of Stephen Covey's The 7 Habits of Highly Effective People is to Begin with the End in Mind. This infographic from BigThunk and Number 8 Communications does just that - recognizing that you need to establish your goals first when looking to your social media marketing strategy.
I especially appreciate this infographic because it doesn't simply speak about conversions - it speaks to the other business uses of social media: Brand Marketing, Thought Leaderhsip, Service and Sales Prospecting. Much of the strength of social media doesn't come from the immediate push... it's the echos and volume that are established over time.