The Cannes Lions International Festival of Creativity earned $59 million (£41m) in 2014, up from $43 million (£30m)—or 37%—in 2012, according to a prospectus released by parent company Ascential in preparation for its IPO on the London Stock Exchange.

Though full-year revenues were not available for 2015, the festival’s revenues in the first three quarters of the year increased $9.2 million (£6.4m) over the same period in 2014. Revenues for 2013 were not disclosed. 

The disclosure form released on Tuesday provides a first-time glimpse into the financial performance and growth strategy of the ad industry’s most prestigious — and expensive — awards show. 

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The festival shows healthy year-over-year revenue growth, due in part to a “self-reinforcing business model” in which agencies must compete to win Lions because they have convinced clients of their value, the document says.

“Agencies themselves have promoted the awards such that their clients now recognise a Lion as the barometer of an agency’s creative talent, and agencies consequently compete to win Lions and market their Lions wins to their clients, reinforcing the circle,” the prospectus says. 

Though longtime Lions participants may find little in the 240-page document they didn’t already suspect, it nonetheless provides confirmation of the festival’s financial dependence on agencies and their clients—which goes far beyond mere entry and delegate fees. For example, the prospectus boasts of business advantages such as “creative firms who promote the festival for their own marketing purposes at no cost to Cannes Lions,” industry players who “suggest speaking slots and pay all speaker fees” and “eminent creatives who donate their time free of cost” to act as judges. 

As evidence of the strategy’s effectiveness, Ascential cites its Customer Value Retention rate—the amount of money repeat customers spend at consecutive festivals—as an impressive 94% for 2015. From 2012 to 2014, the festival’s yield per delegate increased by a compound annual growth rate of 8%, and award entries per yield increased by 10%.

See also: Lions Health entries increase by 30% in 2015

 Though the prospectus doesn’t include a breakdown of revenue streams for the Cannes Lions Festival itself, an itemization of Ascential’s entire Exhibitions & Festivals division—of which the Cannes Lions is the largest event (30% of revenue) —does provide clues. In 2014, the division generated 47% of its revenue from selling exhibition space, 19% from delegate fees, 14% from award entries, 7% from sponsorship fees and 12% from other services. 

Laying out plans for future growth, the prospectus details a strategy that will be familiar to agency creatives: new categories, more VIP delegate options and expanded late fees. 

“The group intends to increase customer numbers by developing new products to attract new customers and leverage existing products to enter adjacent end-markets,” the prospectus states. “For example, the group intends to continue to utilize Cannes Lions’ brand prominence and customer relationships to develop new propositions like Lions Innovation and thereby attract new customers in adjacent end-markets.” 

Launched in 2015, Lions Innovation attracted 845 award entries and 485 paying delegates, 63% of which were new to the festival. Lions Health, launched in 2014, generated $1.9 million in revenue last year.

Entry fees for the 2016 Lions range from about $600 to $1,400, placing them in the top tier of ad industry award shows. Entry fees for the 2016 Clios range from $500 to $1,000, and Effies fees run from about $500 to $1300. All such shows offer the option to file past deadline for those willing to pay an expanded fee. 

Cannes Lions is seen as one of the most prized assets in the Ascential empire, which also owns trade shows Money20/20 and Bett, titles such as Drapers, Nursing Times and Retail Week, and the retail data company WGSN. According to the prospectus, it accounted for 13% of total group revenue in 2014.

This story originally in Campaign.