Portsmouth's support is famously loud and Fratton Park in full voice is one of the better atmospheres in English football, helped by a tight ground surrounded by terraced streets. The south coast derby with Southampton is the fixture the city lives for. Pompey spent years in the lower divisions, and their supporters know better than most how little of that football gets shown on standard packages. Being a navy city, Portsmouth also has a large population with connections overseas and corresponding demand for channels that domestic providers do not carry. Those two things together, lower-league coverage and international channels, are the practical reasons people here look past the usual options.
Portsmouth is the most densely populated city in the country outside London, built largely on Portsea Island, and the housing reflects that: tight terraced streets across Southsea and Fratton with a very high rented share, and limited scope for installing anything. Coverage across the island is reasonable, extending out through Cosham towards Havant and across to Gosport. Being a navy city, there is a large transient population with connections overseas and corresponding demand for international channels. Between the terraced density, the rental churn and that demand, the useful 24 hours is spent checking the channels from elsewhere as much as the football.