Lindzi Shanks was working toward a PhD in psychology when a holiday pop-up changed the calendar. A part-time helper brought homemade marshmallow treats to sell next to mugs.

Customers came back for the treats. She and a co-founder put in about $100 each, packed orders themselves and took every pop-up they could find.

That side project became what she calls the first marshmallow cafe, with monthly sales she puts in the hundreds of thousands. She also says 70-to-80-hour weeks hurt her health and her relationships before the shop looked stable.

One product and a long week

The Upflip episode is about listening to the item people actually reordered and about the cost of the hours it took to keep up.

The monthly sales figure is hers. The start was a treat that outsold the mugs at a holiday table.