We definitely had more thanks to having direct billing set up with our local university. I would definitely recommend exploring that option with local institutions of higher learning, corporate offices, even local government. After a few guests got the word back to some of the key people at the university, we started getting most if not all of their bookings. Everything is taken care of for the department heads and other folks since I just send the statement to the university finance department and they then cut me a check. There's a couple of weeks lag time but I save any credit card fees, too.
Whatever you can do to make it easier for whoever is making travel arrangements, the guest, and the billing person will make you a hit!