The 14th edition of the tournament is well under way at the moment and is proving far more successful than the last time it graced these shores 13 years ago.
Then, hampered by weather, the World Cup proved a financial disaster and left the RFL in debt.
There are no such problems this time around, though, with RFL chief Barwick revealing the tournament is set to make a profit.
The former Football Association chief executive has been "thrilled to bits" by the opening two weeks of the competition and is excited by its potential legacy for the sport.
"We are absolutely delighted with it," Barwick said, speaking at the Nolan Partners Sport Industry Breakfast Club.
"It has exceeded our expectations in terms of the amount of people going to the games, the level of media interest and the quality of the games as well.
"I mean, there were over 10,000 at Leigh last night for Tonga versus the Cook Islands and we're up to 70,000 tickets for the final.
"We have been astonished. We have had sell-outs at Rochdale, Warrington and Avignon, we've had two sell-outs at Workington. We've had the highest crowds to watch rugby league in Cumbria for 20 years.
"We had nearly 8,000 at Bristol, which is not a rugby league hotspot, and we've had terrific media audiences.
"Both the games England played on the BBC peaked at over two million. These are new figures for us.
"I think this is a legacy from 2012 (Olympics). I think people have got into the idea of going to events.
"They may stay with us forever, they not stay with us forever, but I think people like to go to events.
"We have a team of volunteers - that's a legacy of last year and they are loving being part of it.
"I think the trick with rugby league is that it is a world-class sport but has a real family feel to it.
"It has more than exceeded our expectations. We are thrilled with it."
Barwick was joined on the panel by Debbie Jevans, who was director of sport of the London 2012 organising committee.
Now she is the chief executive officer of England Rugby 2015, which is preparing for the Rugby World Cup in rugby union in two years time by working closely with the RFL.
"Sally Bolton, who is the managing director of the Rugby League World Cup, is doing a brilliant job," Jevans said.
"We have met on several occasions and, yes, we have an observer team, who were there at the opening match and we're very integrated in that delivery, as we should be.
"I think many of the points Brian makes come across to rugby union as well, certainly the values of the sport.
"You've got these fantastic athletes that are all over each other on the field of play and then will have a beer afterwards. I think that's something very, very important.
"In 2015 we want to celebrate those values in a similar way to what is happening in 2013, making sure that we do get more people into the game, understanding it and being involved with is, not just as a spectator."