Today I met with a firm called Localeze that provides local directory submissions.  I understand the importance of this service if your site is competing locally, however I'm not sure the effects of local SEO for a national brand.

Our firm gets most of our traffic from across the country, not just one location, and our business is scattered (which is a good thing).  We rank for service related keywords that are not tied to a location.

We do not show up for local results so our business in our immediate location is weak.  We would like to increase our local presence in search engines but I want to make sure that this will not take away from our national presence.

Will optimizing a site for local search negatively affect general rankings?

Thanks