Wall Street - Agents?

Hello Everyone - Hollywood has them. Sports has them. Music Industry has them. Does Wall Street have Agents and if so how do they work? I know the industry has Agents because my buddy from college worked at a firm that classified itself as a firm that acted as "Agents" - for Wall Street professionals. Apparently there was no fees for the customer it was all paid for by the companies looking to hire to expand the clients business. Can someone please describe how this works? Thanks.