The company "Potomac" at http://www.potomac.com and http://www.linkedin.com/company/potomacofficial does not provide specific details about its services or target audience based on the given URLs. However, if it is related to the historical Potomac Company, it might focus on infrastructure or transportation improvements. Without direct access to the company's content, it's challenging to define its unique selling proposition (USP) or services. Typically, a USP would highlight what sets the company apart from competitors, such as innovative solutions or specialized expertise. Further research is needed to provide accurate information.