Online mattress retailer Helix Sleep’s value proposition hits on several trends that resonate with a millennial audience: health and personalization, says co-founder Adam Tishman.

Helix sells mattresses that are customized to each consumer based on a sleep quiz  it asks shoppers to complete. The quiz asks questions such as a consumer’s height, weight, and sleep preferences—for example, if he likes to sleep on his back, side or stomach, if he typically gets cold or hot in the night, if he tosses and turns during the night, if he prefers a soft or firm mattress, plus opinions about his current mattress.

“That messaging our company has—to provide a better night’s sleep with a personalized product—resonates with [millennials],” Tishman says. “The millennial consumer is health conscious, and they understand that health is important and you need a good night’s sleep to be healthy.”

Millennials—consumers roughly ages 20-37 or born 1981-1997, according to Pew Research Center—represent a “large group” of Helix Sleep’s customer base, Tishman says. Roughly 41.2% of HelixSleep.com visitors fall in that age range, as 26.9% of visitors are ages 25-34, and 14.3% are 18-24, according to web measurement firm SimilarWeb’s global desktop data between November 2017-January 2018.

“We all don’t sleep exactly the same. This concept resonates, and it intuitively makes sense,” Tishman says. “We all don’t fit into the same clothing, we don’t all have the same diet, so why are we creating the same sleeping product for everyone?”

The quiz provides data that an algorithm can use to map the shopper’s preferences to one of a “double-digit number” of mattresses, Tishman says without revealing how many different mattresses Helix has. The mattresses are not made-to-order because that would be challenging with its supply chain, Tishman says. The retailer updates the algorithm mapping based on customer feedback, surveys, focus groups and returns.

The mattresses, which are manufactured in the United States, are made “like a layer cake,” and the retailer changes the material in each layer depending on the shopper’s answers. The mattress also can be customized on each side to accommodate two sleepers in the bed.

“Trying to make the average for everyone, you don’t make the right mattress for anyone,”  says Tishman, referring to the importance of personalization.

Similar to other online mattress retailers, Helix Sleep ships its bed in a box and offers a 100-night sleep trial. Helix Sleep has raised a little less than $8.5 million in funding, Tishman says.

He would not comment if the retailer is profitable or on its sales or growth, only that “sales are good” and has had “great growth since we launched.” Helix Sleep launched in 2014 and has more than 5,500 customer reviews of its product.

The retailer has one showroom in New York City. About 245,500 consumers visit HelixSleep.com per month, on average between November-January according to SimilarWeb.

Internet Retailer estimates that Helix Sleep’s sales were $50 million in 2016, according to Internet Retailer’s Top500Guide.com, and the retailer is ranked No. 427 in the Internet Retailer 2017 Top 1000.

A queen-sized mattress at Helix starts at $995, which is similar to other online-only mattress retailers, such as a $940 starting price for a queen-sized mattress at Leesa Sleep LLC (No. 348), $600 for a queen mattress at Casper (No. 182) or $575 for a queen mattress at Tuft and Needle (No. 287).

Tishman, however, notes that Helix Sleep’s price point should be compared with mattress retailers that are customized to each consumer’s sleep preferences, such as Sleep Number Corp., which has queen mattress that starts at $899 and increases to $3,000.