Having sold Klein bottles from my website for 20 years and from Amazon from 4 or 5 years, here's my experience:

- it's way more fun through my Kleinbottle website. I've customized my checkout to what I sell. When there's a problem, it's easier to contact a buyer.

- I can show any amount of information on my website; Amazon has 5 bullet points and 1000 characters of description. This, of course, cuts both ways - a quick logical summary helps many people. Long, wordy websites (ahem) can be a problem.

- Amazon provides security that you'll get what they've ordered. Buying through my website, well, some people are scared off by its primitive style and mathematical humor. (well, attempted humor).

- My credit card processor takes a < 3% haircut. With Amazon, it's 12% plus $40/month.

- My customers are my friends. Likely, I'll meet them at a seminar, colloquium, or if they visit the East Bay. I hope they'll remember me by the good service that I try to provide. This tends to be easier when I handle an order through my website.

Oh man, you are a legend to me! I deeply appreciate you and I remember that the first purchase I ever made on the internet 20 years ago was one of your klein bottles! It was such a scary but amazing first experience. It seemed so magical at the time, to buy an object from the other side of the world! As a teenager I had to convince my dad to use his credit card. We were afraid to send the credit card number by email, and we used a fax machine by your suggestion.

The bottle arrived broken and we were dismayed. We sent you a careful report with photos of the packaging and the broken bottle (real film photos, that we had to develop and then scan into the computer to produce an email). You were so kind to send a new bottle and even said sorry. I was amazed by your reply and by the fact that people so far away could be kind to each other. It really blew my mind. At the time, in my country, the internet was seen as a really unsafe place were you were not supposed to ever say your real name.

To this day, I keep both bottles you sent as my most prized possessions. The cracked one is actually cooler, and the crack has been growing (you can make the crack grow by pressing slightly with the thumb). In a few years it will break the bottle apart in a topologically interesting way.

Of course, Enrique! I'm tickled that you remember me - and delighted that both Kleinbots have survived across the years.

I do check every item that I send out -- I hold it up to a bright light looking for cracks - but sometimes trouble sneaks through. I'll do my best to fix things - replace, refund, or solve a differential equation (ODE, not PDE's, please).

You, in turn, have a responsibility to spread the good word -- I hope you're teaching & making this too-mundane world into a better place.

Across two decades, my warm wishes to you.

      -Cliff

You're absolutely right. but very few sellers are like you. (That's part of why we love you so much.) Outside the small "art" industry, almost none are like you.

I actually remember visiting your site at one point, and I think this is a case where going through a seller is a net advantage :)

I see it not really on the "shopping" experience, and more as you point out because as a buyer I'd need/want way more information than what Amazon will ever provide on a single page, and also because there is a context surrounding the product that is far far away from a "just buy" transaction.

I also see some hobby sites like Bricklink as something Amazon will never be a replacement of. Fundamentally I think specific seller sites are needed.