What are the advantages of subsidy publishing?
This saves you having to buy a block of ISBNs (see explanation). You don’t have to form a company/corporation (see explanation). Often (but not always), the subsidy press has services to help your product look more professional, like editing and cover design (see explanations). Many subsidy presses also have distribution (see explanation) and marketing services (see explanation) you can use (pay for). You can get the trade leverage of being with a multi-title company that you cant get as a 1-book publisher.
