Well, we've drifted pretty far off-topic... sorry 'bout that. But here we are...
The customer's enthusiasm is critical. I try to encourage it.
Indeed. Take a look at the Beckerheads... they have patches, t-shirts, bottle openers, organize both sanctioned and independent gatherings a couple times a year, all kinds of fun stuff. And the swag didn't cost Ka-Bar or Becker a nickle, those folks simply got permission and set it all up themselves. (Ka-Bar/Becker does support all that with knife GAWs/contests, etc.) Point is, very few of those cats only own one or two Beckers... many of them have several, even dozens, and they're almost tireless in encouraging new folks to get into 'em. That's the main thing to take from it. :thumbup:
Most of us don't have quite that kind of scale to deal with, so probably no one is going to design/print/distribute our advertising for free

...but I do think fostering the enjoyment of owning your work and even building a sense of community can be helpful. Think of it as a "value-added" feature...
The further extreme is the Busse company. They're famous for regular sales, specials, secret meetings, purposely limiting certain editions and so forth. At Blade they had people packed around their booth screaming like a rock concert, reserved an entire restaurant and set up a buffet in the hall to feed their customers, lotteries... all sorts of crazy stuff to make people feel exclusive and special.
That sort of marketing is a bit much for my taste. But it sure seems to be working for them, they seem to sell everything they can make at what appears to be a pretty good profit margin.