Fear of flyering: Why are so few of the Edinburgh festival flyers actually funny?

Of all the irritants hardy Edinburgh festival-goers must put up with (in between the 24-hour entertainment on tap and endless parties), the continual assault by chirpy people handing out flyers comes high on the list of sour gripes. Throughout August, pacing the Royal Mile between shows at the Assembly in the New Town and up on the Pleasance is akin to running a particularly wacky and ingratiating gauntlet. But it's not just the crazily face-painted, juggling students in drag on stilts which irk, it's the flyers themselves. Why do comedians choose to advertise themselves with such low-rent, uninformative and frankly unfunny material?

"Unlike at any other festival, flyering really works here," says Miriam Attwood, press and marketing officer for the Fringe. "Because there are so many shows to choose from, it's really tough just to go into the programme and pick a show, so flyers become an important tool." It's a marketing strategy that the Fringe's 18,792 performers have clearly taken to heart. Will Wood, print room and street team manager for the Pleasance, which stages over 200 shows at its two main venues, estimates that each show prints some 500 posters and 5,000 flyers (with some printing up to 20,000 flyers). Consider that there are 2,088 shows across the other 245 venues on the Fringe and the statistics become mind-boggling.

Yet a surprising lack of effort seems to go into creating this essential marketing gimmick. There are honourable exceptions – Aindrias de Staic, the Irish fiddler who hand-draws his flyers and only gives them out to people he trusts; Josie Long, the queen of the whimsical anecdote, who crams her flyers with her cute cartoons; and the super-cool, cult chanteuse Camille, pictured in gorgeous monochrome with a vampy gash of red lipstick for The Dark Angel.

For the most part comedians fall back on a stock garish, full-length shot, often topped by a long-winded title which makes no sense until you've seen the show – and little more afterwards. Culprits range from Rob Deering's disturbing Photoshop portrait of his head atop a busty female body, a nauseating close-up of Craig Hill on a bright pink background and Russell Kane, an if.comedy award nominee, pulling a silly face astride a cartoon chasm for his show, Gaping Flaws. Though one should no more judge a show by its flyer than a book by its cover, sometimes it can be useful to know what's coming. At least Brendon Burns, last year's if.comedy award winner, gives fair warning of his show's shock factor. The flyer for last year's show, So I Suppose This is Offensive Now, depicting the Australian stand-up variously in a wheelchair, nailed to a cross and "blacked up" with a bone through his nose, was all part of an elaborate joke on the audience. And Lucy Porter's frequently sexualised self-portraits – in this year's, Bare Necessities, she is naked but for a pair of furry paws while in others she dons a saucy burlesque corset – at least point to the confessional nature of her stand-up. For the rest, the gurning, heavy-handed portraits not only do nothing to reflect the subtlety of the stand-up's art and humour, they also rely on punters recognising the comedians which, in the vast majority of cases, they won't.

The film poster spoof is another popular stand-by. Reginald D Hunter stars in No Country for Grown Men and Wendy Wason has recreated Audrey Hepburn's Breakfast at Tiffany's pose. But newcomer Susan Calman is alone in pushing the joke beyond the simply visual as she wields a samurai sword on a Kill Bill-style background for her show entitled Maybe it is Your Fault.

So what are the alternatives? Last year Ricky Gervais encapsulated his on-stage arrogance with a giant billboard stating "Ricky Gervais At Edinburgh Castle Is Sold Out – What A Pointless Billboard", while in 2006 Tim Vine took out a prime spot on Cowgate with a banner which screamed in massive light-bulb lettering, "Tim Vine", followed by the small print "... is not appearing at this year's Edinburgh Fringe Festival", gaining him plaudits for the best marketing gag of the Fringe – and he wasn't even there.

Until they buck up their ideas for their flyers, comedians will continue to be reliant on the trusty street teams who work around the clock handing them out. "People always ask us what the show's like," says one hardy soul. "We're always honest but we have to be very diplomatic. We wouldn't say 'it's not very good', we'd say something like, 'in my opinion, this is a show I wouldn't pay to see.'" Comedians – you have been warned.

The Edinburgh Fringe runs to 25 August