For the right client, I do "limited service agreements" (that's the current name for this type of arrangement). It can be just a listing in the MLS or a larger package of services offered a la carte. Actually, this is quite common for owners that have on site sales offices (like new construction or apartment communities) and for professional investors. But, because there are so many legal pitfalls involved, I don't offer it for everyone. They have to really know what they are doing as sellers/landlords.