The National Theatre is repeating its £10 ticket offer next year because it proved such a success in the summer.
Jerry Springer: The Opera helped bring a new audience to the theatre
Theatre fans were able to see Kenneth Branagh in David Mamet's Edmond and a version of Shakespeare's Henry V set in modern-day Iraq for only £10.
A spokeswoman said the theatre had discovered a third of the people who saw Henry V had never booked tickets at the National before.
Next year £10 tickets for another four plays will be offered.
The National Theatre's season was a gamble by the theatre's artistic director Nicholas Hytner as a way of filling more challenging plays at the complex's main theatre, the Olivier auditorium.
Funding came from a sponsorship deal with currency exchange chain Travelex.
Mr Hytner also wanted to attract more young people to the National Theatre, which also features the Cottesloe and Lyttleton theatres.
Two-thirds of the audience for Jerry Springer: The Opera, which had a successful run earlier this year, was under 35, and nearly half of them had never been to the National Theatre before.
Branagh's version of Mamet's Edmond was a huge hit
"We have been very keen to make sure all three theatres are full," the spokeswoman told BBC News Online. "We have 2,500 seats to fill every night.
"It's been a big thing that the Travelex Season attracted so many new people."
But she said the interest was not limited to plays featuring big names, she said.
"We think that the programme has helped the smaller plays at the Cottesloe as well, and none of the actors there are big names like Kenneth Branagh is. It is a good way for us to get people in and show them what else is going on."