Real estate agents CAN give you a referral, but cannot accept any payment for doing so.

Telling a home buyer that "I recommend this guy because I've seen his good work." is a completely different thing than the kickback schemes so many try.

Having been a Realtor, and maintaining my license, I got a lot of referrals from agents. A good agent will realize that you can make them look good, same as a builder can see the benefit.

Other trades will see this same advantage, as they too can get solid referrals.

You show up on time, do quality work, it reflects well on them. They in turn get referrals. Makes the world go round.