We have a small business - my husband makes decals for model airplanes, mostly airliners. He does very high quality work. (Honestly.) So of course we hardly make any profit at all. (I've often thought we should be a non-profit!) We generally do only 500 of each subject as the market is pretty small.
Yet, we have received Cease & Desist letters from American Airlines.
We would be more than willing to let them proof the quality of our products. Instead, they want us to pay them upwards of $1,000 (which is more than the profit we make on an entire run!).
Of course there are companies (usually big companies) that pay American Airlines' licensing fees - But for the most part, the quality seems to suck! So it's not the quality that American is worried about. It's $$$.
And trademark is supposed to be about not creating confusion about corporate identity ie. no other airlines should be able to call themselves American Airlines and use their logo, etc. But we are not pretending to be an airline!!!