I like the idea of moving some of the risk from the job-seeker to the job-offerer. If the developer gets a hotel room for a week in SF and the trip ends up not resulting in a job, he or she is out hundreds of dollars, and that risk might discourage people from visiting from outside of the bay area. There might be a huge number of developers right on the edge where it doesn't quite make sense for them to take a trip to SF, but free room and board would bring them in. Employers are already throwing tens of thousands per employee at recruiting, so this little investment might make a huge difference compared to other recruiting tactics.