EB-1C was created specifically for managers and executives who meet L-1A nonimmigrant standards and are interested in becoming lawful permanent residents. (L-1A status facilitates a temporary stay in the U.S. for intracompany executive or managerial transferees.) The principal distinction between L-1A and EB-1C is that the latter affords the alien beneficiary permanent residence.
In general, an EB-1C visa is a convenient way for a small or start-up overseas company to expand its business and services to the United States.