Where in the world is Loudoun County?
One of the difficulties in creating marketing and communications messages using automated Internet tools and "Web 2.0" strategies, is that not all geospatial technologies have yet become "smart" enough from a semantic perspective. What we mean, is that if one uses online tools to describe an area of the country (like "Dulles South") that doesn't fall neatly into geopolitical boundaries (i.e. "intergeostitial"), or isn't recognized via major geospatial services with specific latitude/longitude boundaries, the online tool isn't likely to understand what you mean. People understand what you mean, if you write about it with good contextual descriptions, but locator services aren't all yet leveraging the most advanced information sources and semantic indexing technologies.
Here's an example - it seems "Loudoun County" doesn't exist in the world (in Mixx's view, "we couldn't find Loudoun County, VA anywhere in the United States")...
So, now that we've described it to Mixx, we've done our small part in establishing another online gateway to Loudoun - make sure you do your part!