Create a Powerpoint presentation about facebook and its impact on local business.
There are various social media stuff available on forums such as warrior forum.
It includes presentations, brochures, business cards to show you as a perfect social media expert.
It also depends on the kind of business someone has whether facebook will be useful for them.
You can also show them examples on how their competitors are using facebook and other social media sites to engage customers.
Most importantly, you need to show them conversions that facebook traffic gets converted into potential customers for a business.