BSkyB now has more than eight million subscribers, the company has announced.
Sky's live football coverage is a draw for viewers
The company had set the figure as a target for it to achieve by the end of the year.
Almost one in three households now pays for the satellite broadcaster's channels, and the company wants to see this rise to 10 million by 2010.
It also wants a quarter of its customers to be using Sky+, which allows viewers to pause live TV and record satellite broadcasts.
At present more than one million people use the service.
Chief executive James Murdoch said: "Sky is achieving strong growth. Nearly one in three homes and counting have chosen Sky and we are especially well placed to broaden Sky's appeal as entertainment and communications come together."
Sky's figures do not include customers who have its "Freesat from Sky" free satellite package, or customers who have let their subscriptions lapse but continue to use their dishes to watch free channels.
Earlier this month media watchdog Ofcom found almost two-thirds of UK homes had access to digital TV, either through Sky's satellite service, through their aerials via Freeview, or via cable or internet connections.
Freeview was available in five million households at the beginning of 2005.
But Sky will face more further competition if cable giant NTL merges with Virgin Mobile to create an entertainment and communications giant.
With nine million customers, it would be likely to pose a threat to Sky's dominance of the UK's pay-TV market.