There seem good advantages in POD (Print On Demand) publishing. I discuss some issues in POD at http://pages.bangor.ac.uk/~mas010/orderbook.html
I have found createspace.com a good publisher for my book "Topology and Groupoids"; they are an amazon.com company, and this has the implication that the royalty rates are good (black and white, 6" x 9", 200 pages, price 20.00 dollars, gives $8.75 royalty). Non exclusive contract.
You should consult the e-book "The Fine Print", written by a copyright lawyer, Mark Levine.
All the publicity, and sending out review and complimentary copies, has to be done by you - this is a typical downside to any self publishing.