They're a great source of information. For example, Dear Editor is holding a giveaway for a FREE Fiction Edit (for Adult, YA, or MG). Deadline to enter is April 21.
As much as we all want an agent, things don't always go swimmingly with an agent, and new associations must be made.
I discovered the Writers Workshop for children's writers hosted by the Highlights Foundation and held each summer at the Chautauqua Institute. Intensive sessions with major players in the children's publishing world. Wow!
I discovered that the Highlights Foundation offers scholarships to help defray the cost of said workshop. (Thank you Toby!)
I learned to apply for things (like said scholarship) even if I didn't think I had a chance in the world of getting them. Sometimes you do.
Sometimes, editors don't want to buy the book you proposed; they want you to write something else, and they'll buy that.
Release dates change, sometimes just days before the originally scheduled date.
Writers are amazing, supportive people, and I'm proud to call many of the people in my network friends.
What benefits do you see in networking?