They get some cut or other, but it comes from the company they sign you with, not from your end per se. Same way as a dedicated agent for just one company would.
Like Dave, I had State Farm for like 55 years or something, for cars, homes, apartment. But got into a hopeless flap with them over a secondary policy about 4 years ago, over a separate policy on guns as a matter of fact, pissed me off so bad I walked out and went over to a biggie independent agency here in Knoxville, called TIS (started many years ago as Tennessee Insurance Co, now just the initials are the name).
Gal suggested best deal was SAFECO, because they are gun friendly, meaning your firearms are part of the overall coverage on your homeowners or rental policy, so don't need a separate valuable items policy. I got significantly more auto coverage for less price, and renter's was bout same, but actually a much better deal what with the guns being covered as part of it.
You'd almost certainly get a lot more for your money if you do both autos and home policies.
They cover folks in 47 of the 50 states, can likely take you on from just with phone/email, call em if interested:
http://www.tisins.com/
- OS