An investment in social media doesn't offer the same potential for immediate returns as traditional media does. There is no social media equivalent of buying a spot in a TV show for next week, or a placement in a newspaper for tomorrow. The lack of consolidation of influence and power in social media creates a system where the potential for immediate return is limited.
Because of this reality there is a lag time between the investment in social media and the return. If you start building a presence now, don't expect it to be a significant driver of your business in three months. You can't buy relationships the way you used to be able to buy attention. The reach and influence that you build within social media communities and networks takes consistency and commitment to develop.
You can't buy social media like you can traditional media, you have to build it. And it always takes longer to build something yourself than to buy it from someone else. If you understand this concept, you can realize a huge return on your social investment, but only if you start investing before you actually need it.