A business card or badge should be as close to flat as is possible. With the new features I am adding I want to provide convenient connections without adding to the thickness of the assembled board. A 4mm plated through hole with an oversized pad is ideal for this application. It is probably the most utilitarian connector you can put on a PCB. It adds zero height and zero cost, and it works with banana plugs, alligator clip, and screws. Banana plugs are the perfect connection for a multi-meter.