Julep, a Seattle-based cosmetics start-up, is constantly launching new products--about 25 a month. How does it prevent flops? By testing customer demand in several different ways:

Idea Lab

About 5,000 customers have joined Julep’s Idea Lab. Once a week, the product development team sends them an email survey, asking what they want in, say, a mascara. “For instance, do they want lengthening, curling, thickness?” says founder Jane Park. “A lot of times, there are compromises we have to make.”

Online Advertisements

Julep frequently places text ads on Google for not-yet-available products to see which marketing message gets the most clicks.

Social-Media Surveys

Every month, Julep asks its fans on Facebook and Instagram to vote on which products they prefer. The results aren’t always a reliable indicator of sales, says Park, but customers like being involved in decisions.

Testing Parlors

In the Seattle area, Julep operates four nail parlors in which it tests products in development on paying customers. “You can get a lot of great data online, but sometimes it’s nice to get firsthand feedback,” says Park. After salon customers raved about a new skin-repair serum, Julep marketed the product online. It quickly became one of the brand’s top sellers.