We present a new mass estimate for the Hercules dwarf spheroidal galaxy ( dSph ) , based on the revised velocity dispersion obtained by Adén et al . ( 1 ) . The removal of a significant foreground contamination using newly acquired Strömgren photometry has resulted in a reduced velocity dispersion . Using this new velocity dispersion of 3.72 \pm 0.91 { km s ^ { -1 } } , we find a mass of M _ { 300 } = 1.9 ^ { +1.1 } _ { -0.8 } \times 10 ^ { 6 } M _ { \odot } within the central 300 pc , which is also the half-light radius , and a mass of M _ { 433 } = 3.7 _ { -1.6 } ^ { +2.2 } \times 10 ^ { 6 } M _ { \odot } within the reach of our data to 433 pc , significantly lower than previous estimates . We derive an overall mass-to-light ratio of M _ { 433 } / L = 103 ^ { +83 } _ { -48 } [ M _ { \odot } / L _ { \odot } ] . Our mass estimate calls into question recent claims of a common mass scale for dSph galaxies . Additionally , we find tentative evidence for a velocity gradient in our kinematic data of 16 \pm 3 km s ^ { -1 } kpc ^ { -1 } , and evidence of an asymmetric extension in the light distribution at \sim 0.5 kpc . We explore the possibility that these features are due to tidal interactions with the Milky Way . We show that there is a self-consistent model in which Hercules has an assumed tidal radius of r _ { t } = 485 pc , an orbital pericentre of r _ { p } = 18.5 \pm 5 kpc , and a mass within r _ { t } of M _ { \mathrm { tid } ,r _ { t } } = 5.2 _ { -2.7 } ^ { +2.7 } \times 10 ^ { 6 } M _ { \odot } . Proper motions are required to test this model . Although we can not exclude models in which Hercules contains no dark matter , we argue that Hercules is more likely to be a dark matter dominated system which is currently experiencing some tidal disturbance of its outer parts .