OK it is probably not possible. Is there a company that can do it--or any way possible--to include about 10 tiny petunia seeds glued to a sales brochure? Or flyer for hand passing? Your guys aren't busy this month, right? Suppose, you put a dot of glue, on the last paragraph of your brochure--and then put pinch of petunia seeds on the spot --allowing the rest to fall back into your big bowl of seed. Or one zinnia seed or some kind of specially good seed. Butterfly plant? Grass seed? Seeds of mole-chasing plant? For simplicity, the customer cuts off the last paragraph and buries it in her garden. Of course, helpful printed lawn and garden information and tips (perhaps customized for your town) would be far easier. Would your potential customers appreciate knowing the average last and first frost dates for your town? Growing zone? Best times to plant flowers, or when to prune roses? How to water grass for reduced disease? Anything to get the potential sales lead to hang onto the mailer or flyer.