If you think that's a typo, then you're probably over 40, or don't have kids.

On a sunny Friday, about 600 disciples of the god of saccharine tween pop, Justin Bieber, lined the city streets to grab a piece of merchandise in honour of his Purpose Tour.

Bieber, who will perform before more than 10,000 no doubt shrieking fans at Etihad Stadium on Friday night, arrived in Perth earlier this week for a string of shows.

The merchandise on sale at the pop-up at the Sneakerboy store on Little Bourke Street runs from Friday to Sunday.

Items include hoodies and T-shirts, with prices ranging from $15 for buttons to $130 for sweatshirts.

Chloe Camporeale, 14, of Adelaide, had been in the line for three hours. She planned to spend $180 when she eventually reached the store.

Wearing a Bieber T-shirt, she said she was excited to see the "perfect" star in concert for the second time.

"When I was 12 I couldn't even see my wall [it was so covered in Bieber posters]. But I've gone a bit more neutral now."

Shelby Osmond, from the US city of Atlanta, has followed the Purpose tour through London and to Australia.

She and her friend Adriane King found out about the merchandise shop on Instagram.

"We've been waiting since 8.09am; we want to get a top that says 'Melbourne' on it."

Last year, rapper Kanye West drew crowds of thousands in pouring rain to Fitzroy for a pop-up store to sell merchandise under his Pablo label.

Unlike the West event, Friday's Bieber crowd was about 90 per cent women under 25.