Do you have a presence on twitter? DC (and metro area) is the #1 socially connected city COUNTRY! If you do have twitter, make it better known and interact with those already living here as well as those thinking of moving here.
Space out facebook postings, often i will get 5+ posts in a row... and then read none of them. Most FB users check at lunch and in the evenings and weekends.
Articles back to the main site are good/necessary, but would also like to see questions, banter, humor - get people interacting