Here's something to test.

Take your existing business-to-business direct mail package and make just one change: put two windows on the mailing envelope instead of one. Mail it and see what happens.

According to direct mail author, publisher and speaker René Gnam, "two windows usually get more attention and response than a single window.” In tests that René conducted for his clients, two (or more) windows on the carrier envelope increased response rates. The increased sales also paid for the added cost of producing the special envelopes.

Some direct marketers use one window to show the recipient's name and address, and the other window to reveal something tantalizing. This is a classic use for extra windows to tease prospects into opening your envelope. The secret is to show something of value or immediacy through the window so that prospects are compelled to open the envelope rather than lay it aside or pitch it.

What to show through the extra window:

• gift certificate
• discount coupon
• photo of your back-end premium
• deadline for taking action
• invitation to a special event
• title of a white paper or report
• CD-ROM or DVD
• front-end premium
• special offer
• prospect's name on a certificate
• teaser copy ("Reserved for [prospect name] . . .”)
• a swatch of material
• name of the mutual acquaintance who referred you
• something else (use your great imagination!)

Why limit

You could use more than two windows, of course. René Gnam once used four windows and saw an increase in response. Use as many as you can think of. Just make sure they don't break your production budget!

You are also not limited to putting windows on just the front of the carrier envelope. Why not put one on the back as well, with something intriguing peering through? Check with your post office or mail shop to be sure that the envelope will still be machine-readable and qualify for postage discounts (assuming you are mailing large quantities).