If imitation is the sincerest form of flattery, Rotterdam's CineMart must be one of the most admired events in the film world.

Now in its 24th edition, the co-production market has spawned a host of similar events. These range from the Berlinale Co-Production Market to the Pusan Promotion Plan (PPP), and markets from Manheim to Rome. There is L'Atelier Du Festival in Cannes, and the New York Film Festival has its own co-production market modelled on Rotterdam. This year, London will also stage its first co-production bazaar (details will be announced during the Berlinale).

It is easy to see the attraction of co-production markets. They help lure industry delegates to film festivals, they are gilt-edged networking opportunities and they enable independent movies to find finance. Business can be done formally and informally, through the inevitable chance encounters with potential partners. The digital age has done nothing to reduce the attraction. "What co-production markets offer is a good old-fashioned hub where people can meet face to face, honestly and frankly," notes one producer.

"CineMart remains the best organised but also the most rigorous in terms of selection," UK producer Keith Griffiths suggests. "(But) it's not a magic wand. It still takes forever to patch the jigsaw of these productions together."

Despite the buzz of co-production markets, not many deals are announced while the events are in progress. "I've never gone anticipating coming back with the Godardian cheque written on the serviette, but the networking can't be underestimated," Griffiths observes.

Raising finance may be slow, but every year, projects that have passed through CineMart turn up in official selection at major festivals. Recent examples include Lou Ye's Summer Palace, Jia Zhangke's Still Life, Mahamat-Saleh Haroun's Daratt and Rodrigo Moreno's El Custodio.

Some believe there are now too many co-production markets. "There are many of these markets and they are not all of the same level," says Philippe Bober of Paris-based The Coproduction Office. Like Griffiths, he still regards CineMart as the pre-eminent event of its kind. "Rotterdam has managed to attract the core business in the arthouse world. It's not necessarily the place where you are going to sign deals, but it is a very good place to launch a project."

Bober has been associated with many CineMart titles, among them Roy Andersson's Songs From The Second Floor, Lars von Trier's Breaking The Waves and Lou Ye's Suzhou River. On the latter title, he says CineMart played a vital part in getting the film financed.

Rotterdam's advantage over some larger festivals is that it offers attendees less frenzied surroundings in which to do business. Pusan's PPP and the Cannes Atelier also receive praise for their environs. "Cannes has created a little oasis with the Atelier within all that frenzy. It's sharply different and productive," says Griffiths.

One producer expresses strong reservations about the "fad" for co-production markets. "Every year, there are one or two more," he laments. "At some, you're supposed to have a large amount of money already attached but there are projects that are there with no money at all and some are there without a script."

The message is clear: unless co-production markets are as selective and as rigorously organised as Rotterdam, they risk leaving attendees dissatisfied. "There's a danger the co-production market can become a fashion accessory attached to many festivals," says Griffiths. "Many festivals don't realise how much money and staff time is required to administer and make these things work properly."