Single-ended signaling is less expensive to implement than differential, but it has a distinct disadvantage: a single-ended system requires a power supply voltage equal to the maximum amplitude of the signal to be received whereas a differential system only requires a voltage half of the signal amplitude to be received.
A disadvantage of single-ended systems that utilize a common return is that the return currents for all the signals use the same conductor (even if separate ground wires are used, the grounds are inevitably connected together at each end), and this can sometimes cause interference (crosstalk) between the signals.
The effects of capacitance and inductance, which filter out high-frequency signals, limit the speed.
Historically, electrical telegraph used single-ended signaling with earth return, thus completely eliminating the need to provide a return conductor and substantially reducing the cost of long distance lines.
Telegraph is the earliest use of the single-ended transmission line type, but is now obsolete.