Before your potential customers send in their order for your main product or service, think about making a second sale using real estate on your business reply envelope (BRE). Make it interactive - by creating a bangtail BRE.
Here's an example of a bangtail BRE that recently arrived in my Bank of America credit card statement (you may have seen this piece if you're a Bank of America customer; it's been mailing for quite some time) ...
This is the reply envelope that we're supposed to use to return our credit card payment. But instead of just taking our payments, this envelope contains a special offer - and tries to make another sale. It starts to reel me by piquing my interest with a "please remove to reveal value" sticker. Half of the sticker is affixed on the back flap of the BRE. The other half of the sticker hides part of an insert that is folded and nested inside of the BRE.
In this example, the insert that is nested inside of the BRE is about the size of a buckslip and contains copy promoting a complimentary $20.00 gift card - which I can get just for trying Buyers Advantage(R), an added service that Bank of America offers their customers to help protect their purchases, get the lowest prices, and more.
Here I am with a "Direct Mail Minute" talking about this piece ...
(Note - This example is rather complicated! Bank of America spent some buck$$$ creating this piece - but since they send it to a high volume of people, the production costs are brought down to scale. Nevertheless, many marketers with smaller production budgets can still do a bangtail by extending the back flap of the BRE a couple of inches and adding a perforation - thereby turning the flap into a reply form that can be returned in the original BRE for the second offer or sale.)