THE sex industry is taking a spanking from online dating websites providing "adult" contacts with minimal costs to customers, according to business analysts. Adult dating sites such as adultmatchmaker.com.au allow people to find sexual partners without the "moral difficulties" of visiting a brothel, said analysts IBISWorld. "Internet sites promoting sexual rendezvous between strangers with no exchange of funds have seen strong growth in recent years," said IBISWorld general manager Jason Baker. "These negate the need to pay for sexual gratification and sidestep many of the moral difficulties posed by soliciting prostitutes, making them a popular alternative." But while the industry's traditional customers – young men – were spending more time hooking up online, Mr Baker said the number of female clients was set to grow.