My own experience has been that fliers or cards delivered individually to residences elicit a greater level of response than they do when delivered as part of a "pack" - mixed in with other commercial solicitations. As to working with real estate brokers, I think it's the one-to-one contact rather than any printed material left in brokers' offices that generates business. The initial contact can lead to doing business on a kind of relationship basis, which is much stronger than simply mailing out pieces to various offices, then waiting for a response.