A co-publishing agreement means that while the music publisher has ownership in the copyright and administers its exploitation, another publisher (possibly a songwriter’s own company) controls the other piece of the publisher’s share of ownership. This type of agreement often happens when established songwriters who have a lot of power within the industry establish their own publishing entity and enter in an agreement with another publisher.
The New Formula for Success in the Music Business
The old method of promoting a new act in the music business was for a record company to invest at least $500,000 in studio time with a good producer, the cost of a good video, the advertising budget, and the cost of the first promotional road tour.

