Members-only e-commerce site Touch of Modern has launched its own line of products.

The flash-sale retailer, No. 259 in the Internet Retailer 2016 Top 500 Guide, now sells three house brands of T-shirts: Pillars of Thought, Edge Industries and Dapperman. The company began quietly testing private-label products toward the end of last year.

“I wouldn’t say it’s a big fraction of our business, but it’s been growing by 20% month over month so far,” co-founder and CEO Jerry Hum says of the new brands. “We’re going to be going at it very deliberately. It’s one product at a time, not one category at a time.”

Hum says the company will decide which manufacturers to use to make its branded products on a case-by-case basis and not operate from a set list.

“Part of our sourcing strategy is we have a ‘hit list’ of [ products ] we want to put on our site, and we go and look for those things. Sometimes we find it through a third party and sometimes we don’t.”

Hum says selling private-label merchandise makes sense given that Touch of Modern has an established e-commerce platform and knows what its shoppers want. “We can offer a better quality product at a better (profit) margin because of that,” he says.

The private-label products are designed to keep shoppers coming back to TouchofModern.com, Hum says. “The recurring theme with us is you grow by having good customer retention,” he says. “These are the products that our customers want to come back and keep buying.”

Touch of Modern generated an Internet Retailer-estimated $100 million in sales in 2015, up 233% from $30 million in 2014.