In his role as head of the AFL Commission, he was responsible for a number of changes, including the expansion of the league from 16 to 18 teams, the restructuring of the tribunal system, and the brokering of two new television rights deals.

[3] In 2008, Demetriou earned an annual salary of $1.4 million, making him the highest paid administrator or player then employed by the AFL.

The deal included unprecedented live TV coverage of the AFL competition in all states of Australia through free-to-air, subscription and IP television.

[11] In the first half of 2005, Demetriou criticised the Sydney Swans and then-coach Paul Roos, labelling the team's play as "unattractive" and "ugly".

[citation needed] He claimed that the Swans would not win the premiership with the way they were playing,[12] and this statement was underlined when the team suffered a 43-point defeat to St Kilda in Round 10.

[15] Seven years later, Demetriou praised the Swans for their new attacking style of play under second-year coach John Longmire and rated them as serious contenders for the premiership.

[19] Demetriou has interests in factories in Brazil and India which manufacture dental products and exports them to 70 markets, including Australia.

[23] Mr Demetriou was sued by shareholders for his part in the collapse, and contributed $360,000 to the settlement sum to stop the Court action.

In 2021, Demetriou resigned after Crown was found by Commissioner Patricia Bergin on behalf of the NSW Independent Liquor & Gaming Authority not to be suitable to hold a gaming licence in New South Wales and specifically found that Demetriou was someone who Crown "would be justified in lacking confidence in", calling his evidence to the inquiry "bizarre" and "unimpressive".