21-year-old ran his side hustle from his parents’ apartment—now it brings in over $500,000 a year

This story is part of CNBC Make It’s Six-Figure Side Hustle series, where people with lucrative side hustles break down the routines and habits they’ve used to make money on top of their full-time jobs. Got a story to tell? Let us know! Email us at [email protected].

Three years ago, Jason Siu was a high school student selling $3 stickers on Snapchat to save up for new parts for his car.

Today, the very same side hustle, called Invalid.jp, brings in more than $500,000 per year. It still sells stickers, along with flashy car accessories ranging from LED-lined rearview mirrors to cupholders, visors and license plates.

Siu, now a 21-year-old college junior at the University of Hawaii at Manoa, buys most of those items wholesale, customizes them with light panels or homemade designs, and resells them for a profit. A few months ago, he rented a warehouse to serve as the business’ center of operations, he says. Before then, he ran Invalid.jp from his parents’ 1,000-square-foot two-bedroom apartment in Honolulu.

He’s pocketed about $400,000 from his business since it started, he estimates. Some of it comes from TikTok virality. A popular video of Invalid.jp’s light-up stickers, posted in 2022, led to $38,000 in sales in a single day, Siu says.

He credits his relentless posting strategy, honed over the course of multiple years.

“A lot of times, people I talk to trying to start businesses only try for four or five months and [quit when] it doesn’t work,” Siu tells CNBC Make It. “Everyone’s trying to go viral for their business, but if you post one to two videos every day for a month, that’s 30 to 60 videos. One of them is bound to go viral.”

Siu doesn’t bring in tens of thousands of dollars every day, so over the past couple years, he’s also learned how to make his business more consistently profitable — often leaning on social media ads to help raise Invalid.jp’s revenue floor.

Here, Siu discusses how he turned his side hustle into a six-figure-a-year business, what it takes to launch your own version and the No. 1 piece of advice he wishes he knew upon starting.

CNBC Make It: Do you think your side hustle is replicable?

Siu: Yes. It’s all about consistency.

In the early days, I was pushing out more content and products — quantity over quality. We’d post so many videos that were between five and eight seconds long.

It was definitely effective in the short run. Once I had one video go viral, I saw the potential and felt like I could replicate the result as long as I kept posting. But then I had a problem: Some months I’d only bring in a couple hundred dollars.

Now it’s more [about] quality. I’ll vlog or post longer videos about how you use a product, or [what it’s like] to unbox it. I’ve invested more into [social media ads] and hired a couple contractors to help me film content.

How much cash do you need to start this side hustle?

I wouldn’t say [more than] $100. When I first started, I ordered product for like $20 and filmed videos every day. When it works, you buy more inventory and ship it out.

You can figure out what’s trending by looking on Amazon or TikTok, or you can film and post videos and see if it goes viral. But you have to know that what you buy has the potential to sell. It’s a risk to buy a bunch of inventory before knowing people like the product.

What’s the most important trait you need to succeed with this kind of side hustle? What do you wish you’d known at the beginning?

I’d say persistence. I used to work [for a valet car service] from 9 to 5. I thought starting my own business would help me work less. When you’re doing a side hustle, you’re going to be working 24/7. You’re going to work more than you ever have.

When I first launched the LED mirrors, other people were making similar products and doing pretty well — but they couldn’t keep up with demand. Once, when I was packing all day, I [realized], “Not many other people would do this.” I filled up my [parents’] whole living room with boxes and packaging.

There’s no hack. It’s really about finding the right product and your creatives, your videos.

This interview has been edited for length and clarity.

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