We have these discussions many times before - Newcastle has a massive catchment area - possibly three times the Boro's. I have lived and worked in the area, OK for 13 months but its a major city, economically and culturally it has been the major centre of the North East for at least 500 years.
Actually a lot closer.Newcastle's catchment is roughly 3 times Boro's as you say, Sunderland is roughly twice the size of Boro's, and by some mathematical magic their historical average attendances are roughly three and two times the size of Boro's respectively (actually less, but for the sake of argument). We do alright considering we're a club with no real history of success, unlike the two up the road who back when Noah was an amoeba were actually successful clubs.