80what it is good for
Pure decoration. The bubbles do nothing, cost nothing and never run out, so the only thing to plan is where they end up. They pop the instant they touch a block or a character, which means a machine crammed into a tight room produces a thin, stuttery effect. Give it open air above and they rise properly and drift sideways with whatever the world wind is doing that day.
It takes wire, and hooking it up is worth doing even in a purely cosmetic build. A freshly placed machine starts running on its own, so without a switch you have no way to turn it off, and a permanently bubbling room gets old fast. One lever by the door solves it. Buying one means catching the Party Girl during her shop hours.