Amazon Smile trades ad views for 1% of their proceeds to a non-profit of your choice (including the FSF, EFF, and more, though I think RMS would have a seizure accepting this money)
Whole Foods gives you significant discounts on hot foods if you scan a QR code from the app (still expensive though).
I don't use these personally but I can totally see someone using them.
Nginx is 2-clause BSD, which I would argue is more "Open Source" than Arch Linux (official repo contains proprietary components such as discord, steam, multimedia codecs). You could argue that the majority of it (and it's build system) is open source, but probably not "Arch Linux" is fully Open Source.