According to this article: 

A report by Industry analysts IBISWorld predicted the 2008-09 financial year would see strong growth for brothels, strip clubs and prostitutes, primarily on the back of a marked increase in tourism levels to Sydney as a result of...

Here's a clue, it's not the annual Masturbate-a-thon.

It's the Catholic Church's World Youth Day!

When contacted for comment, "Ramada Khawley, function manager for strip clubs such as Men's Gallery and Pure Platinum, said she was not expecting an upswing in trading."

"We're not making any special preparations for World Youth Day," she said.

"But we'll keep a table reserved for the Pope."