3D Printers typically have SD or MicroSD slots for uploading STLs for unattended printing. Most electronic music equipment like keyboards, synths or sampler pads have SD/MicroSD as well. Hell a lot of shop tools like CNC mills and welders have SD Card slots. Don't most Action Cameras use SD or MicroSD? Most professional grade video cameras will record simultaneously to multiple media formats and one of those is always an SD Card. Anyone tinkering with a Raspberry Pi is going to need an SD reader too. If you're doing any data logging with embedded micro controllers then you're probably using SD or MicroSD as well.