Data transport capacities of fiber based optical transmission systems with conventional phase insensitive optical amplification and phase sensitive parametric amplification are compared using the Shannon capacity formula to identify the better suited amplifier concept. Due to lower noise figures of phase sensitive amplifiers, up to 3 dB higher signal-to-noise ratios at the link output can be achieved with phase sensitive amplification than with phase insensitive amplification in the same link configuration. Thus, phase sensitive parametric amplification enables a transmission of more bit/s/Hz in the signal channels, but it also requires additional bandwidth for the transmission of idler channels. Different application scenarios are studied and guidelines are derived for the selection of the better suited lumped linear amplifier concept for the respective system type.