It's one thing when a relocation company is involved and they've offered their client a bonus in the transaction in return for the company referring their business to an agent. Then their company receives a percentage of the agent's commission to help pay that bonus. Although this type of business sharply cuts into the agents wages, it has become one of the types of business that is pretty accepted.
It's quite another thing when people set up internet sites and advertise that they can find a super agent for you if you register and give them your information. Then the person in charge of the internet site takes the realtor's business and trys to sell it back to them by trying to get them to pay a fee up front to just get the possible lead and then pay a referral fee also if a sale is made. This kind of action is just someone trying to attach themselves to the real estate industry and make money off the agents.
If you need an agent, mouth to mouth referrals is a great way, or call a local company or two and interview a couple of agents and make your decision. If you're working with a realtor and moving to another state, let that realtor find another realtor for you. That way, the realtor will find a high quality agent for you. Don't try to find your agent from some internet site where someone is just sitting there behind a computer trying to tap into the real estate industry to earn extra money.
Generally speaking, the people on the internet sites wouldn't know a good realtor from a bad one, they're just selling names. At least your current realtor can check the roster of their company and talk to the Broker in the town or area you prefer and find someone to fit your needs and watch over you.