An aware producer is always on the lookout for new and appropriate material for their clients. Careful networking and perseverance will play heavily into the song writers success. Many producers are artists themselves and understand the total business from both sides. Soliciting your material through a producer may be the best way to get your material into the right hands. If your material has already been published, the producer is still invaluable.
Some producers are also publishers that creates a different situation.
The material you have published needs to get into the hands of the producers that will actively work to find the act or project to use your material. If a producers focus was only to find the act or project for your material, your material sometimes will be produce more quickly. If the producer is also a publisher, the focus may be to have a commission on your material for someone else to produce. You want to get your material in the hands of a producer that won't sit back and let someone else produce your music while they receive income on the publishing. Many say there is a balance between the smaller production agencies and the larger agencies.