"I bought this for my HVLP sprayer, which only has a 1.5m cable. Previously I'd just plugged it into an extension reel, but if I wanted to move the sprayer I'd have to move the reel as well - awkward and wasting time. Now I can move my sprayer around the room quickly and easily.
This would also be ideal for moving a steam stripper around a room. Again, I've used an extension reel, but that's not ideal as you're using water close to it. But with this longer cable you can cover the extension reel somewhere and just move the steam unit around.
My only criticism is of myself, why didn't I buy one years ago!"