Women are quitting their jobs and instead, they're selling their used underwear.

When Piper Chapman and her fellow female inmates starting selling their used underwear online for profit, we all let out a collective ‘huh’.

“Is that…is that even a thing?” we asked ourselves.

Turns out, it very much is, and business is booming thanks to the popularity of Netflix show Orange Is The New Black.

According to Alex (who prefers his surname go undisclosed), who started the site SofiaGray.com with his business partner, this business has boomed since the third season of the show went to air.

"The storyline did send a surge of traffic to our site during the months it aired. We have no idea who the buyers are, nor do we want to know. We keep all buyers completely anonymous," he told news.com.au.

Alex says many women use the site as a side income, with one user this week making $6,500 for a single pair of used underwear.

"Some sellers have supplemented this to be their side income and some have made this their full time job. It really depends on how much you put in...you could see hundreds if not thousands in a month," Alex said.

Alex is just one of many who is cashing in on the trend; while selling used panties online is nothing new, the practice has skyrocketed in popularity since OITNB made it 'mainstream'.

In fact, Google experienced the biggest spike ever in the search time 'sell used panties' when the show dropped on Netflix.

One website, Pantydeal.com, experienced ten times the normal amount of sign-ups to their service in a single day after Piper and her friends started their business in the show, according to VICE.

While the trend is nothing new, and certainly not everyone's cup of tea, Alex believes we shouldn't judge those who engage (and enjoy) the practice.

"Our response is that everyone is different and can’t control what they like. If it’s not harming anyone and all parties are consenting adults, I see no problem with it," he said.