The final of Big Brother's last regular series, featuring the launch of Ultimate Big Brother, was watched by an average of 4.1 million people, according to early viewing figures.
That compares with an average of 3.23 million who saw last year's final.
A peak of 4.6 million tuned in for the closing stages, when faces from Big Brother's past followed this year's winner, Josie Gibson, into the house.
They include singer Preston and his ex-wife Chantelle Houghton.
Financial sales rep Gibson, 25, from Bristol, who received 77.5% of the votes, is favourite to go on and win the title of ultimate Big Brother housemate.
She was followed back into the house by Houghton and then Preston, whose romance blossomed on Celebrity Big Brother 2006.
"You look so much shorter," Houghton told the singer as they hugged.
"Do you come here often?" he asked.
The couple were among 11 former contestants to be put back into the house for the new 18-day series.
Racing pundit John McCririck, 70, told host Davina McCall he was "only in it for the money" as he re-entered the compound.
Other former contestants from the celebrity version of the show to feature in the new series include US rapper Coolio and former weather presenter Ulrika Jonsson, who was champion in 2009.
"Nasty" Nick Bateman from the first series of Big Brother - wearing a t-shirt emblazoned with the words "it's only a game show" - was booed by the crowd.
Former winners Brian Dowling, of Big Brother 2, and Nadia Almada, of Big Brother 5, are also in the house.
The line-up is completed by Makosi Musambasi and Nikki Grahame, who failed to win but made an impact on viewers.
McCall said before the end of the programme that two more former housemates would enter the house on Friday night - but not through the front door.