That's great! Some small things about your website:

- "Contact" page says "Kontact" in en-GB locale

- Do you need a shopping cart for one product? Just have the "buy it now" and leave the cart out?

- Do you need a search? There are only a couple of pages.

- The Contact page might want to highlight to the user that there is a chat feature in the bottom right, if they prefer that to email.

Other than those little bits, the site looks pretty good to me! Payments seem slick. Have you done things like ProductHunt?

Yes, your website has two user hostile features which immediately make me want to click away

1) Sending cookies to track me, and then a big lie about how you "value my privacy" while trying to track me and sell my data to your "partners"

" ► UpPromote Affiliate Marketing [Application] - Running..."

2) A cookie banner, which you completely ignore as you've already set 7 cookies before your javascript craps out ("TypeError: a.R is undefined"). At this point I haven't done a single thing on your page worthy of even a session cookie.

3) Once you "decline" your banner (which doesn't stop those cookies - including cookies you have set for 12 months in the future), you get a "chat" window with a red notification icon

> But marketing is extremely important and it’s just a very different skill than tech.

I once watched my father sell a single christmas lightbulb to another guy on a garage sale in the middle of july. "I convinced him he needed it" After that day I paid attention to sales. Some people just have that knack for it. They naturally know all the techniques and when to use them and how to properly use them. There used to be a very nice wikipedia article that broke most of them down but it looks like that page is gone (or I can not find it).

Seeing that you're German, too, I would suggest that you try to reach out to some newspapers. I know that's extremely old school, but it worked well for us. newsaktuell.de/ots is a service where you can send in a press release (and pay) and they'll distribute it to newspaper reporters for you. Also, they offer "Native Advertising" which is basically that you write an article about yourself and they'll pretend as if it was objective news written by them.

And lastly, did you know that you can contact your local IHK and they will report about you in their membership magazine? You probably already pay for the IHK and you probably already get their magazine. A calender seems like something that other CEOs would want to hear about, so this might actually be great content for their magazine. And just like you, every other company owner is also a mandatory IHK magazine subscriber ;)