Developing a National SEO Strategy involves the same principals as Local SEO but on a much larger scale. You need someone to show you what to do, or you'll spend a boatload of time and money and have very little to show for it.
People who need your product or service find your business. They may not know your product, service, or even the type of product or service exists. However, they find you nevertheless. Now all you have to do is convince them that your product or service works and your business is their best choice.
People who have a particular need or problem interact and network with people with the same needs or problems. This adds the best sales tool of all... word of mouth either directly or via social networking.
Directly contacting social media outlets related to people with special needs is another important aspect of Inbound Marketing.