Attracting well-known events to a city can be very helpful in raising the profile of the region, but it often comes at a significant cost. Take the Olympics for example, a huge event that has exceeded the budget of every city that has hosted it since 1960.

Research undertaken by economists Victor Matheson and Robert Baade on the benefits of the Olympics, meanwhile, shows that while there are gains, they are usually few and far between.

“Overwhelmingly, studies show actual economic impacts that are either close to zero or a fraction of those predicted before the event,” they wrote in an article published in 2016.

So what about another event that, although far from the size of the Olympics, has become a key annual gathering? When Web Summit moved from Dublin to Lisbon in 2016, there was much mourning over the loss of a major technology conference. This was despite the fact that it had grown too big for the Irish capital.

At this year’s event, Bobby Healy, founder of Irish drone delivery start-up Manna, lamented that Dublin had lost the event. “Web Summit is a giant Irish success story. It’s a shame that Portugal Inc is taking most of the benefits, ”he said.

New official figures reveal that Portugal is indeed benefiting from Web Summit hosting, but far less than it had hoped. A study found that the event generated 115 million euros in additional revenue for the country and 252 million euros in VAT. Some 6,895 jobs were also said to have been created as a result of the conference in Lisbon.

If these are impressive figures, they are 77.5 million euros less than expected in revenue and 196 million euros in VAT less than initially expected. In addition, 2,673 fewer jobs than expected were created.

The Web Summit deal with Lisbon is set to last until 2028, so those predictions could still be good. Or we may have passed the peak of the Web Summit. Time will tell us.