Mexican Grand Prix chiefs insist that a sell-out crowd for this year's Formula 1 race will not allow them to believe their job is done in securing the event's long-term future.
Interest in F1's return to Mexico for the first time since 1992 has caught race organisers by surprise, with general admission tickets being snapped up within a matter of minutes when they were released earlier this year.
But despite a 300,000 weekend attendance predicted for the GP, track bosses know that their real challenge comes in keeping audiences coming back from 2016 onwards.
Federico Gonzalez, the Mexican GP's managing director, told Motorsport.com in an exclusive interview: "There are several reasons why this year is such a success.
"We haven't had the race for 23 years, so that helps. We have a 20 million population in the city, which helps. And the prices are reasonable, which helps. It is a bunch of things that help.
"But the real challenge is to keep that spirit of fans continuously going to the race. That is the most challenging thing, not the first one. The first event is all happiness. The challenge will come over the following years."
Sell-out in minutes
Although Mexico has not hosted an F1 race since 1992, interest in the sport has been boosted by the presence of drivers Sergio Perez and Esteban Gutierrez in recent years.
Rodrigo Sanchez, director of marketing, said that ticket sales could not have gone better – as the circuit evaluates adding more grandstands.
"We launched our ticket sales in March and the response was just astonishing," he said.
"Not wishing to sound cocky or anything, I think we were expecting a good reaction, because I think we did our homework well. But the response was just astonishing.
"Within minutes, 3-5 minutes in some cases, the tickets sold out in a majority of the areas – so it has been great. It has been a great experience…."
Sanchez said that although the sale of tickets was a success, it was important that Mexico now delivered a great fan experience to ensure people came back in the future
"Right now the focus is to fully execute a successful GP," he said. "We have done well on ticket sales but it is not the end. There is still so much to do.
"For us, we need to guarantee that the experience at the track is a world class experience, that people are happy, and that international people who come get a true taste of what Mexico is.
"From there we need to look at years two, three, four or five."
Help to American foothold
Preparations for the Mexican GP are on schedule, with the new asphalt being laid this week and preparation on the pit and paddock facility now 75 per cent complete.
Sanchez thinks that the fact Mexico is forming a double-header with Austin will be a boost to the sport on the American continent.
"I think it reinforces the message of F1 in America. As you know, at European races, there is a strong tradition of F1 because they have been consistently having races in these places for many, many years.
"On the American continent, we haven't had the fortune of continuity of F1 throughout the years.
"This is the third time that F1 comes to Mexico. We had our first round in the 1960's, then the 1980's and early 1990's and then after 23 years F1 will be back to Mexico in 2015.
"In the USA, they have jumped from Dallas to Detroit to Phoenix to Indy to Austin. There was talk about New Jersey, but there hasn't really been a consistent face of 15-20 years of F1 in the American continent overall.
"For us, having a partner like Austin reinforces the message. It creates more fanbase and it is really important to try to reach out to the new fanbase and kids especially. In the end, this new fanbase will be the next generation of ticket buyers."