Number of clients per agent

I think it's typically somewhere between 20-40, but much of that will depend on the agent and the specific clients. (If most of their authors produce work slowly, they may have more than an agent whose authors all produce at least one book a year.)

Mine also has clients in a number of different sub-genres. He reps graphic novel artists and authors, romance authors, mystery/thriller authors, SF/F authors, and a few non-fiction folks. This does mean he has to have a broad range of contacts, but it also means he's not constantly sending material to the same handful of editors.

This is so difficult to answer, as there are so many variables. But in my experience the better agents have fewer clients and tend to work very deeply with each one, making a high number of foreign and subsidiary rights sales per title.

The best agents I know personally don't have more than around twenty author-clients. I do know good ones with forty clients, but the more clients an agent has the less time she has to devote to each one, and that's bound to have an effect on the number of rights sold for each title--and on the agent's ability to persist in selling a title which has already received rejections.

I wrote this blog post some time ago, and stand by it: http://literaticat.blogspot.co.uk/2014/11/how-many-is-too-many.html

From what i've read its between 15-40, the ones with fifteen typically have just started out, the ones with 30+ have had many of their clients for a very long time.