As Explained by Mollie Glick
1. Publishers don’t often handle unsolicited works – at least big publishers, that is. There are too many manuscripts for editors to look through every one.
In addition, it’s a copyright issue. She said Hyperion, which is owned by Disney, will not even look at an unsolicited ms because of the fear of being sued. They will only deal with agents.
2. Agents have “intense relationships” with editors—that’s their job. Agents track where editors go, take note of what they like, know where they grew up, if they have kids, etc. Agents realize that fiction is a very subjective thing so they try to get to know not only editors’ tastes, but also them as people. She has lunch three times a week with editors.
3. Agents can help negotiate a bigger deal. The contracts that publishers use are not easy to understand. This is for a reason. She also added that some publisher royalty statements are “almost incomprehensible” – again, no coincidence.
Agents are a step removed. They can play “bad cop” with an editor or house if need be. If the editor wants to change the book’s title, for example, and you (the writer) hate the decision, Mollie will step in and play bad cop. It allows you to stay removed from the argument so you can keep on good, editing-only terms with the editor.