She sends off up to 50 packages of clothing each week and is now at the threshold where she must register to pay GST for the business. She already pays income tax.
In December Mrs Coursey hired a seamstress to help sew all the clothes she creates in her kitchen, orders for which come from across New Zealand, Australia and even as far afield as Canada and England.
When Punk Baby Clothing began, Mrs Coursey tried selling the clothes on Trade Me but sales were slow until she switched back to Facebook and began marketing the site.
She set up a website but says 98 per cent of orders still come through Facebook, where a business page is free and interactive.
Using social media Mrs Coursey has collaborated with other sellers to attract more followers.
However she said Facebook was fickle.
"They make changes all the time. I don't put all my faith in Facebook although it's been really good to me, anything could happen because it's a free service."
Her advice for other would-be Facebook entrepreneurs is to "stick with something you know".
"Go with what you like and don't try to ride on anyone else's coat-tails."
Hamilton-based beauty therapy student Tami Boroevich started a Facebook business selling vintage and new jewellery she made only four weeks ago.
Already she has earned $400 in sales from her page Once Upon A Time.
She has only 227 "likes" but expects the number of followers to increase as she continues creating the designs.
Ms Boroevich writes weekly status updates, has plans to introduce more accessories, will do giveaways and"likes" other pages to help increase her presence.
The former small business owner chose Facebook over Trade Me or a personal website because it was free and "the in thing".
It was also a way to test the market without committing too much time and money.
Employers and Manufacturers Association spokesman Gilbert Peterson said that people who used social media to garner business were "innovative and creative".
However, Mr Peterson said disadvantages included negative comments being posted on your site.
"You could open yourself to some attack from a competitor. But since it's free you're offsetting the risk of some people logging negative material on your product."
Mr Peterson said the businesses were mostly small, one-person operations and a good way for people to "get started" before establishing a website.