There are all sorts of online listing services, whether you choose to try and market your business yourself, or have an intermediary work for you. I have listed one such resource under the “Links” section on the right hand side of this page. Are they effective? Like any tool, it depends on how you use it, and more importantly, how one follows up with prospects. Just like any industry, “business brokerage” probably has 20% of people that are truly effective, and 80% who are just “pointers.” You might develop an idea of whom you want to work with by perusing advertisements on sites like one I have linked to.