I've previously detailed what Arc offers its writers. When I started to think properly about what publishers in general offer readers I came up with an interestingly contradictory list.
The obvious (to me) advantage is quality control. Books published by Arc and other strong publishers are not only endorsed by the selection process but are also books that have gone through a rigorous editorial process. The reader is secure in the knowledge that the writing will be of a high standard.
On the other hand the reader can take risks. Knowing a certain publisher is a sign of quality means you can dabble with other writers you may not have heard of. Experiment. Take a chance on discovering the work of someone new. We all know that thrill of discovering a writer who you just adore and that realisation you have a whole catalogue of new work to read and enjoy. Series are perfect mechanisms for readers to explore new writers within a certain criteria. We also have a 'If You Like...' tool on the website which connects loosely connectable books for readers.
Whole back catalogue. Yes, a good publisher is a loyal publisher (within the bounds of point 1). At Arc we pride ourselves in remaining loyal to our writers, and so will continue to publish work, beyond the first book - when they are 'new and exciting' to coin a popular phrase. And so be an integral part of a writer's development as they progress through their writing career, so delivering stronger and perhaps more experimental books to readers.
As I mentioned in the earlier post, we support the promotion of writers, so readers can meet them, hear them read their work, talk to them, question them. Not only do we liaise between writer and venue, but also publicise the event. As much as we can...
Through the above and our website, we do what we can to encourage and aid the writer in their own ways to connect with readers.