Ofcom has released figures showing that there were 3,915,000 households receiving Freeview as of September 30 this year.
The media regulator attributed the growth of digital penetration in part to the adoption of second sets.
It said that a quarter of Freeview sales were going to homes that already had switched to digital television, but who were buying set-top boxes to convert second sets in the same house.
The figures showed that 560,000 households switched over to digital for the first time during the quarter, with Sky adding 53,000 subscribers during the period.
That puts BSkyB at almost 7.1m as it closes on its target of 10m. Sky's latest advertising campaign is encouraging customers who already have a set-top box to install another elsewhere in the house.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .