Last month, Rent the Runway, the fashion subscription and rental business, joined the Unicorn Club with a $1 billion valuation based on its most recent investment round.

Then, it quickly announced a plan to model its next phase after the world's biggest online retailer, and to create "the Amazon Prime of rental," as CEO Jennifer Hyman put it to The New York Times at the time.

Now, RTR as it's also known, is unveiling the next category it wants to target with its rental model: children's clothing.

As they did with women's clothing, they'll be focusing for now on the high end of the children's fashion market, much as RTR did originally with women's clothing in 2009.

It later launched a service called Rent the Runway Unlimited, which let women hold onto four pieces of less formal clothing as well, as part of a push to bring their model to everyday wear.

So now, kids--starting next Monday.

"It doesn't make sense to buy expensive clothing for your children when they're growing that quickly," Maureen Sullivan, Rent the Runway's COO, told Adweek. "In some ways, that's where the culture of hand-me-downs came from. Because you buy these beautiful things, and you can't bear that they're not going to get enough use out of them."

The company also announced a foray into rental furniture last month, partnering with West Elm. The children's clothing offerings will start at the high end of the market, too -- at least for now.

The initial brands involved in the children's clothing effort will include Chloe, Fendi, Stella McCartney, Marc Jacobs, and Lilly Pulitzer.

So far, Sullivan said, the company has no plans to offer men's clothing, focusing instead on taking care of everything its core customer -- a "millennial female, busy working woman" - needs.

"We're seeing all these new use cases beyond what we thought we'd do originally, which is get her dressed for work," she told Adweek, adding: "Consumer behavior is shifting. There's a massive cultural trend. ... The experience in the sharing economy has made people realize they don't need to commit to owning so many things."

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