Did you hear the one about the comedians who can't fill a venue?

Nick Clark finds plenty of seats to spare at the quietest Edinburgh Fringe for years

Richard Herring ended one of his Edinburgh Fringe performances this week with a hollow laugh. His show, Talking Cock 2: The Second Coming, had been well received by the 150-strong audience, but large numbers of seats were empty.

"Tell your friends. As you can see, there's plenty of room," the comedian said, adding: "You can have a row to yourself."

Herring is not the only act at Edinburgh labouring to fill venues in a year that has been dubbed one of the worst openings in recent times. Established comedians and critically-acclaimed plays have struggled to sell out, while many looking to make their name are playing to as few as four people in venues that can hold 20 times that.

Theatres are reporting lower ticket sales and promoters are working harder than ever to get their acts noticed by the media or the public.

Herring, who first appeared at the Fringe 25 years ago, said he was "being forced to accept that this is going to be a very quiet year in Edinburgh" and the only consolation was that "it is seemingly the same for everyone".

Venues including Gilded Balloon, Pleasance, Underbelly and Assembly all said ticket sales for shows early in the festival, which began on 3 August and runs until 27 August, were down because they clashed with the Olympics. William Burdett-Coutts, who runs Assembly, said: "During the first week the big comedians weren't selling out at all. Many had big gaps in the audience. It's picking up now but it has been tough."

Attendances for Fringe stalwarts such as the Irish comedian Jason Byrne – normally a top seller – suffered in the first week. One comic said: "Josie Long didn't sell out in her first week. That's just bizarre." Long took to Twitter last night to say: "After spending all day telling everyone that I love my show, 'I've finally hit my stride', had the quietest one yet. You win, Edinburgh."

With big acts failing to sell out, says Herring, there is no "overflow" of punters taking a chance on the less well-known performers. Competition is fierce, with 2,695 shows this year, as well as the Free Fringe. One comedian playing to small audiences said: "Without the TV profile here you are in trouble. Crowds are picky. There are a lot more shows and people aren't going to as many." One young comedian at his first Fringe said his ticket sales were poor. When comforted by a promoter blaming it on the effect of "Suicide Wednesday", he replied: "Yes, and Top Yourself Tuesday and Gun in the Mouth Monday."

Advance ticket sales are in decline, according to promoter Brett Vincent, and acts have struggled. "People are now largely pre-booking only one show and then maybe taking a punt on another. "

He said that while his acts were pulling in the crowds, they had "had to put in a lot more work than most years". "Even last Friday was tough," he added. "Some big shows weren't selling out until the last hour."

However, now that the Olympic s are over, the pace is picking up. Shows featuring TV regulars such as Russell Kane, Phill Jupitus and Marcus Brigstock are selling out this week. Those with Edinburgh followings, including Tim Vine and Daniel Kitson, were also snapped up.

"Sales have picked up and people are booking for the last weekend," Mr Vincent said. More shows are being chalked up as sold out and the buzz has built.

Herring said: "Everyone here needs to have a think about how to address the problems. I'd like to see acts lower their prices and bars, hotels and landlords to do the same."

Case study: 'Loads of us are struggling'

Jen Brister, an experienced stand-up, says 2012 has been the worst of her five years at the Fringe, and if audience numbers stay so low she may pack up. "It's not just me, loads of comedians are struggling," she said. "This is the quietest time I've had. In the past, you'd probably sell out at least one of the days in the first weeks. The idea of selling out now is preposterous. Last year, I had 55 people a night. The most I've had so far is about 30."