how neccesary is a return line for a electric fuel pump?

mattchoy said
do i need to run a return line for my electric fuel pump? the instructions show a diagram without one,but what would be the pros and cons? thanks

red holley pump
eddy carb
318
71 demon

Not that pump as it doesn`t have much volume. You can`t just decide to bypass any old elec. pump just because.........