Despite its push to accelerate online sales, e.l.f. Beauty (ELF) is still seeing its biggest strength at top retailers Walmart (WMT), Target (TGT), and Ulta Beauty (ULTA).

"We're growing our business strongly at Walmart," e.l.f. Beauty CEO Tarang Amin told Yahoo Finance (video above). "We grew our business at Ulta Beauty over 70% last year without any incremental space. And at Target, our longest-standing national retail customer, we're their biggest brand across mass color cosmetics and facial skin care by a pretty wide margin."

In terms of shelf space at retailers, e.l.f. lags other large cosmetics brands with about 12 feet of shelf space at Target, 8 feet at Ulta Beauty, and 7 feet at Walmart. However, e.l.f. plans to add incremental shelf space at Ulta, CVS, and Walgreens in the fall.

In its fiscal fourth quarter, e.l.f. reported that net sales increased 78% year-over-year to $187.4 million. This growth was primarily driven by strength across retail stores as well as e-commerce, according to the company.

"This is our 17th-consecutive quarter of net sales growth," Amin said. "Our business is really resonating with consumers."

Retailers struggle to keep e.l.f.'s viral products in stock

Amin added that the strength of the quarter was driven by demand for new products that in some cases exceeded what retailers could keep on their shelves.

That was the case with some of its viral products, such as e.l.f.'s Beauty Wands, Power Grip Primer, and Halo Glow liquid filter, Amin said.

"We're a viral sensation," he said on the Q4 earnings call. "We couldn't keep them in stock. We actually have quite a few out-of-stocks, just given the strength of the innovation that we've had that builds upon itself."

Due to the brand's affordability factor, e.l.f. continues to be a favorite among teens and Gen Z. However, Amin added, "one of the things we've been seeing is we've been picking up more and more millennials and Gen X."

As e.l.f. continues to pick up new customers, Amin noted he's not concerned about retailer inventories over the long term.

"We have plenty of capacity," he said. "We have incredible partnerships with our key suppliers where we share with them what our future plans and outlook are that they can work against."

"So I think this is a temporary [phenomenon]," Amin added. "[Over] next couple of months, I continue to see elevated out of stocks. But we talked on the call also making the investment of kind of building back up our inventory levels, such that we can continue to serve the tremendous growth that we have."

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