In Massachusetts, unless you have a real estate salesperson's license and work for a broker, or have a real estate broker's license and either work for a brokerage or own a brokerage, you cannot be paid a fee or receive any compensation of any type for leads. Unless you have a real estate license or a licensed brokerage, no payment of any kind. I suspect that the rules are the same in your area.
If you are asking whether someone who is a Realtor (belongs to the National Organization of Realtors) and is licensed to practice real estate in the state in which they gather and try to sell leads, can sell leads to a non-Realtor (not a member of NAR) but who is a licensed real estate agent, then the answer is whatever the agent's brokerage will pay as a referral fee.
In addition, I, as a brokerage owner, refuse to pay for leads. It is a fool's game since it is so easy to run afoul of the above rules, because these lead generators produce garbage leads, and many even try to sell the same garbage leads to multiple agents!