Volume, Zoom, Digital Audio Production knobs, Video/Photoshop timeline or level controls, Gaming, Productivity macro (context switching, app switching, Brightness

Anything that benefits from fine tuned 'back and forth' adjustments that settle on a value in a range.

It's often more satisfying to have 'one motion' control of these functions rather than repeated 'up down' clicks to achieve a desired range.

With a rotary, you can choose the velocity of the adjustment which you cannot do with discrete 'up and down' clicks other than through a 'hold' algorithm or rapid clicking.

Yep, imagine replacing a guitar's whammy bar with a rotary jog dial; not the same

Oh damn. my take-way is that my keyboard needs a whammy bar now.

I hope that encoder's knob is easily removable because it's a large protrusion that will get in the way of slipping the keyboard into narrow spaces. Large coat pockets, outer pockets on backpacks, drawers, bookshelves, ...

It looks like the kind of thing that might get damaged. Imagine it getting stuck when opening a drawer, which someone unwittingly tries to overcome with force.

A rotary encoder can be mapped to the mouse wheel for scrolling documents, reducing the need to move the hand to the mouse to perform that.

As an aside, if that sounds interesting, you can do this with some of the cheap USB volume knobs available from Amazon, etc. that have a configuration menu, e.g. https://hackaday.com/2022/01/20/setup-menu-uses-text-editor-...

I bought one exactly like that, used AutoHotKey to configure it for various productivity applications. By default it mimics my mouse wheel, for more comfortable scrolling.

I don't get it. My minimal keyboards are for travel/mobile set ups. The whole point is to be able to throw it into a bag. This knob makes that impossible.

I’m sure I’d use it as a physical volume knob

I would love to have such a knob be mapped to speed up or slow down/rewind any video or podcast I'm watching or editing on the fly. Unfortunately no software would ever support this, someone would have had to standardized it 20 years ago first.

If OP reads this

Switch out that selector switch for a knob with an indent. Its just annoying and bad feeling to free spin a selector switch like that. For stuff like scrolling and volume adjust, you want to be able to do it effortlessly with one finger.

Example of mentioned knob?

Seems they are called "scrubber knobs" if you google it.

Practical examples: Scrolling a soundwave in Audacity. Scrolling the sequencer in a DAW like FL Studio. Binding it to a MIDI control to play live music. Rotating a 3D model.

What about adjusting the volume? If you have ever been in a car you can instantly relate to a knob like that.

Switching virtual screens jumps to mind for me.

A knob is not a particularly natural or efficient way to do that, however.