I don’t know anything about those labels or their business practices but my impression is they can’t be compared to a traditional music label. As far as I can tell from a quick scan they are just music retailers masquerading under the name music label.
The first thing I would ask is what do those labels actually do to promote the artists? Do they do more than list them on their website, social media, and mailing lists? If not then they are the digital music equivalent of Amway. You would be better off paying someone to build you a website with a CMS and shopping cart system that can sell and deliver digital content instead of paying someone else 60%.
In the book publishing world there are publishing houses called vanity presses. They will print up anything you care to submit, get you an ISDN number, file a copy with the Library of Congress, and offer promotion and sale through their website that is only ever visited by the other authors whose books they publish. They are interesting if you want a professionally made copy of something you’ve written as a gift or whatever. It is not a vehicle for a professional writer, there is a saying, “Be paid to publish, don’t pay TO publish.”
