Soo... a hybrid of donation button and tax on people who don't know about right-click → save image?
It's part of a series of experiments that I've run on monetizing open source, which you can read about in the article I wrote a while back here: https://medium.com/@qrohlf/i-sell-triangles-on-the-internet-...
That said, right-click > save as image is supposed to be disabled on that particular DOM element, but I'm guessing you probably have an extension or user-script that re-enables it. Which is fine, you're probably not the target audience for this! Trianglify.io is mostly used by designers working on professional projects for whom $8 to save 20-30min of tedious work in Illustrator is a very good value proposition.
FYI, even without an extension, you can bypass it being disabled by holding down the shift key while right-clicking (at least in Firefox).
You're right, I do have an extension against common annoyances. Totally forgot about it since I usually screenshot anyways.
Having done some of my own monetizing experiments, I was surprised by how often people don’t make any attempts to circumvent what is written on the site. Text appeared to be much stronger than efforts to prevent free service.
Still, it’s kinda funny to me if this works well enough to make any sales. It’s not possible to prevent download of images you serve, there are several ways to save them in all the major browsers without any plugins. Are you serving the full size image?Intentionally?