By Kevin Young
BBC News website entertainment reporter
When ITV launches an entire channel dedicated to quizzes next month, it will be entering a crowded market for "call-in" programming which has grown rapidly in the past year.
Brian Dowling (centre) is one of ITV Play's hosts
Playing along at home has always been an option with television quiz shows.
Now, however, there are channels entirely devoted to live contests, with viewers urged to call premium rate telephone numbers or send text messages to compete for cash prizes.
Already there are about 15 such services on digital satellite in the UK, while a number of other channels now include similar programming in parts of their schedules.
ITV1, for example, devotes four hours per night to the competition programme Quizmania.
Channel 4 also has a stake in the genre, with the channel Quiz Call run by a subsidiary, while Sky Digital offers a variety of interactive services to satellite subscribers.
TV viewers are encouraged to send text messages to enter quizzes
"Bubbly" presenters create a frantic, high-energy atmosphere as they try to maintain tension over several minutes.
The stakes are often high, with thousands of pounds available in prize money. The questions may be incredibly easy, giving the impression that the money is well within the viewer's grasp.
There is no guarantee, however, that callers will get as far as speaking to the presenter, despite paying as much as £1.50 per minute to take part.
Indeed, Icstis - the organisation that regulates premium rate telephone services in the UK - has acknowledged that the growth in the number of puzzle channels has been "matched by an increase in complaints about them".
Nearly 10% of all enquiries about premium rate services received by Icstis between September and November last year were specifically regarding television contests.
It has also said telephone networks are now receiving "a much larger volume of enquiries and complaints from subscribers who had incurred high phone bills through numerous repeat calls to these services".
In January, Icstis issued a code of practice to broadcasters, requiring greater transparency in displaying the price of a call, the terms and conditions, plus contact details for the competition operator.
Any company wishing to launch a live quiz programme must first gain permission from the regulator.
The Premium Rate Association, a trade organisation for companies operating higher-cost telephone lines, maintains tight regulations mean that TV viewers are generally shielded from scams.
"These quiz shows are proving to be very, very popular and they're run under very strict guidelines," says policy manager Liz Riby.
"The consumer can make an informed choice. The charges are transparent and are pointed appropriately towards their audience."
The lure of a major cash prize can prove attractive - and addictive.
ITV says it hopes viewers will participate in its contests a few times on a regular basis and will stay within a budget, rather than "binge" playing.
It will also have guidelines of its own to "set out how we will deal with ITV Play's consumers".
ITV hopes viewers take part now and again but won't "binge" play
An ITV spokesperson adds: "Our code of conduct means that we will be leading the market and setting new high standards for customer care in this genre."
Standards are certainly an issue, not just in the way that broadcasters operate, but also in the cosmetic appearance of a channel on a television set, with some channels appearing cheap and garish.
Coronation Street quiz
ITV promises ITV Play will be of higher quality than its rivals with "formats that will drive this market to a new level altogether in terms of quality and viewer experience".
These will include Rovers Return, a pub quiz inspired by Coronation Street.
It seems promotions such as these will ensure that quiz channels remain popular for some time yet.
"It's obviously an arena which people enjoy playing in," Liz Riby says. "We welcome the increased choice for consumers that these quizzes offer."