Shoppers on mobile devices helped athletic apparel manufacturer Under Armour Inc. not just protect but also build its financial house in 2015.

Under Armour, whose slogan is “Protect this house,” does not break out online sales figures. But in its Q4 2015 earnings filing Under Armour reported that its direct-to-consumer business, which includes e-commerce, accounted for 36% of its net revenue of $1.171 billion during the fourth quarter, or $421.6 million, up 25.1% from $337.1 million during the same time last year.

During the quarter, Under Armour, No. 121 in the Internet Retailer 2015 Top 500 Guide, also eclipsed the milestone of $1 million in online sales in a single day. The brand achieved that mark in China on, appropriately enough, Singles’ Day, an annual day of online sales every Nov. 11.

For 2015, direct-to-consumer revenue accounted for 30% of total revenue of $3.963 billion, or $1.19 billion, up 27.1% from $936.2 million last year.

CEO Kevin Plank told analysts on the company’s Q4 earnings call that mobile shoppers played a big part in Under Armour’s online sales growth in the U.S. in the quarter, accounting for nearly half of all visits to its website and 23% of online sales.

“Consumers continue to look for us in multiple places,” he told analysts on the call, according to a transcript from Seeking Alpha. “We will be wherever they are, whether it is on a device or in physical stores.”

One of the key growth drivers for online sales has been the success of the company’s Connected Fitness database, which Under Armour claims now has 90 million unique users in the U.S. alone . “Before Connected Fitness, we only had retail transaction information for less than 10 million people, that’s stores and e-commerce combined,” Plank told analysts. “Now, we have daily activity level data from our community members, who logged nearly 8 billion foods and 2 billion activities last year alone.”

Connected Fitness helps consumers keep track of their eating and exercise habits while giving Under Armour access to a wealth of information about those users. “Not only do we have people going into our stores and visiting our e-commerce sites, but we also have a deeper understanding of our consumer based on information collected using Connected Fitness including sleep, fitness, activity, nutrition, weight and ‘how do you feel’,” he said. “This gives us an unparalleled view of their life and needs.”

Women shoppers in particular have been key to the brand’s success online over the course of the past year.

“Women’s was our No. 1 largest-selling and fastest-growing category that we had, faster than men’s and faster than youth,” Plank said. “When we merchandise correctly, we believe we will win.”

Mobile initiatives will continue to be a key area of focus in 2016.

Plank told analysts that the brand’s four app platforms “collectively are earning more than 130,000 new users a day since just the beginning of the year.”

For the fourth quarter ended Dec. 31, Under Armour reported:

• Net revenue of $1.17 billion, up 30.7% from $895.2 million during the same time last year.
• Net income of $105.6 million, up 20.4% from $87.7 million.
• North American revenue of $1.02 billion, up 26.2% from $808.2 million.

For 2015, Under Armour reported:

• Net revenue of $3.96 billion, up 28.6% from $3.08 billion last year.
• Net income of $232.6 million, up 11.8% from $208.0 million.
• North American revenue of $3.46 billion, up 23.6% from $2.80 billion.