Earlier this year, Scott McIntosh was invited to peddle his combination phone/cup holder on TikTok, the social-media app that has attracted 150 million U.S. users.

TikTok was offering to pay for shipping and cover discounts of up to 30%, even though it would pay him full price on each sale. It seemed too good to be true — especially when compared with the fees McIntosh pays to sell his wares on Amazon.com and Walmart.com. The catch: He’d have to make product videos — lots and lots of product videos — and post them to the platform.

McIntosh was floored by the results. His $30 Cell Phone Seats racked up 50 million views, and orders have been gushing in. He generated a record $10,000 in sales on the day after Cyber Monday, has ordered more inventory for the holidays, and expects the momentum to continue into 2024.