St Kilda won the NAB Cup on Saturday night after four weeks of debate over whether or not the competition should be shortened.
Demetriou said there was no evidence either the AFL or primary sponsor NAB would request the format be altered next year, and the league was more than pleased with this year's attendance figures.
"When we start, we've got 16 clubs that all think they've got a chance, and when we get to the second round, there's eight clubs that say they've got a chance and eight clubs that aren't interested in it," Demetriou said on Sunday.
"We've been incredibly thrilled with the response, and not with just the NAB Cup but also with the NAB Challenge. If you go and ask anybody at Narrandera or Albany that got a chance to taste AFL football, you'll just be amazed at the response.
"In Melbourne on a Friday afternoon at four o'clock, to get 10,000 people at Princes Park to watch Chris Judd play a game, and it was covered live on radio and then an after-match conference for a NAB Challenge game.
"Football is alive and well in the pre-season, make no mistake. Last night was a great game and both clubs were desperate to win, and Neil Craig and Ross Lyon were fantastic."
With Saturday night's temperature in Adelaide nudging the 40-degree mark, the Saints opted to spend all three breaks inside the rooms.
They were booed by the South Australian crowd for emerging late before the final term, and consequently may face a penalty by the AFL for delaying the start of the quarter.
"I'm sure that the football operations team will look into it," Demetriou said.
"I understand there were some real issues with heat. I was there last night; it was a hot night.
"They went inside to cool down. We did extend the breaks at quarter time, half time and three-quarter time, so they'll get a report on Tuesday about the length, if it was over. And if it was, I think there's a process in place and they can deal with it."
