The problem with these publishers is that you pay a substantial up front fee for the privilege of them taking most of the profits if your book actually sells.
If there is no up front fee then fine, but it is a bit much to expect the author to take all the risk with the initial costs and then for them to take a cut on all future sales.
If the publishing is through lightening source (as it probably is) the process after title set up is completely automated, the only cost is £8 a year to keep the title in the catalogue so they are really getting cash for doing nothing.