If you build it, they will come. This is the philosophy of developers and entrepreneurs who are flocking to Mid-Market on the wings of Twitter, which famously headquarters there. In the next few years, the long-neglected stretch of Market Street between 5th Street and Van Ness Avenue hopes to draw strangers citywide to its renovated Strand Theatre (expected to open in 2015) and a forthcoming mixed-use complex, to be designed by the Copenhagen architectural firm Bjarke Ingels Group. Already, a slew of new doors are opening, aimed at giving the throngs places to eat and sleep.