(Especially for b-to-b!...)
An envelope without a teaser almost always gets opened. Recipient has to open it to see what it's about... Don't want to miss anything important!
...But an envelope with a teaser? It's instantly recognized as advertising. ... So whether it gets opened (or more likely, tossed) rides on that teaser alone.
In fact, you want to skip the teaser for the same reason you sometimes want to hand-address the envelope, no? ( That is, to make it seem less like advertising and more like personal mail...)
Indeed, you want to skip the teaser for the same reason you sometimes want to mail without a name on the return address, no? ( That is, to spark curiosity about the contents of the envelope...)
...Sure, a teaser can highlight a cut-off date for response ... but otherwise it seems the blank envelope is stronger, especially for b-to-b...
Maybe some of you have more experience with this than I do... Am I overlooking something great about teasers? In what cases would you want to use one? In what cases would you just leave it off?
How about this:
==> If you're promoting your copywriting services, would you use a teaser on the envelope? <==