An 18-year-old brings in $300,000 a month selling 3D printed 'reload can holders.' Here's how he comes up with unique product ideas.

Michael Satterlee is the founder of Cruise Cup, the company behind the viral tactical reload can holder.

Dylan Ethier

• Teenage entrepreneur Michael Satterlee created a "tactical reload can holder" that went viral online.
• His Instagram video, which has over 50 million views, fueled his e-commerce company's explosive growth.
• To come up with unique ideas, start by innovating an existing top-selling product.

Earlier this year, Michael Satterlee posted a video chugging...