@vlastimil
I understand your pain. To paraphrase what 40hz said, if you can't change the situation, change your attitude. I'm not trying to be a Smart Alec — I'm forced into this myself often enough. I find that it helps

Perhaps I'm talking out of turn here, but have you considered consulting mouser about offering a limited-time discount on your software to DC members?
The
up side.
Those offers appear in the newsletter and I firmly believe there's a mutual benefit to that.
- Others who have done this with their products profess to be very satisfied with the results.
- DC members will like you for it (and they're an influential group by and large; many are the designated computer gurus for family, friends etc.).
- Some will buy your product who might never have heard of it.
- If nothing else you get some good publicity at no cost to you.
- The offer is limited to members and not made known to non-members (unless you choose otherwise) so the world in general won't get you product 'on the cheap'.
I think it's a win-win situation.
The
down side.
- There are no guarantees about what might happen in terms of sales.
- DC does not endorse your product, it simply makes members aware of your offer.
- You'll probably get a review of your program by someone on DC, and that will be very frank about likes and dislikes.
- Members who try, and happen not to like your product will probably say so in whatever topic you might announce the offer.
Just a thought…
(edit for typos)