This stupid tip is written to those new to Ubuntu Unity or just who doesn’t know about it.
In Unity, sometimes we want to run another copy of one program from the launcher which is already running. But when click again on the shortcut it doesn’t start another copy, also there’s no option on right-click menu. Although some programs can start another copy from current running one but what if it doesn’t?
Actually, the mouse middle-key or middle-wheel was designed to do the job. Just middle-click on one icon to run another copy if one instance is already running.