Wayfair (W 0.87%) is showing no signs of losing its epic growth momentum. In early May, the online retailer announced another quarter of nearly 50% sales gains as consumers prioritized spending on home furnishings, the niche it is increasingly dominating in the U.S. and Europe.

Let's count five of the ways that Wayfair trounced expectations in the first quarter following a record 2020.

A young woman shopping on a laptop.

Image source: Getty Images.

1. New sales: $1.1 billion

CEO Niraj Shah and his team had predicted that growth might slow for a third straight quarter while still staying elevated year over year. Instead, revenue gains sped up to 49% from 44% in late 2020. Wayfair added $1.1 billion to its first-quarter sales base, pushing revenue up to $3.5 billion.

The chain won market share from a wide range of home improvement and home furnishings retailers, thanks mainly to the proprietary delivery network Wayfair's been building for years. "Our focus remains squarely on connecting ... customers and suppliers on our unique platform," Shah said in a press release .

2. Repeat orders: 71% of all orders

Repeat shoppers accounted for nearly three-quarters of all order volume, which implies high customer satisfaction and loyalty. Success here also helps Wayfair keep advertising costs down, increasing profitability. And it's a sign that the retailer has some enduring competitive advantages against online rivals and established furnishings stores.

3. Gross profit margin: 29% of sales

Gross profit landed at $1 billion, or 29% of sales. That's 4 full percentage points higher than last year, thanks to several positive trends, including rising prices and higher shipping efficiencies. Management had predicted that gross margin might eventually land in a range of 25% to 27% of sales as the business matures, but now Wayfair is saying that 30% margins are possible. "Our strong profitability should not only continue but expand," Shah said.

4. Free cash flow: $111 million

Wayfair has now achieved positive cash flow in each of the last four quarters, including the first quarter, which is normally its weakest cash flow period of the year. This win helped cash holdings rise and is funding aggressive spending in areas like the fulfillment network, tech development, and labor. That's Wayfair's surest path toward maintaining its momentum and staying connected to its huge pool of newly acquired customers.

5. Active user base: 33 million and counting

Wayfair's second-quarter growth trends are tracking lower than last year, which includes some of the biggest demand surges related to COVID-19 retailing shutdowns and federal stimulus measures. But that snap-back decline doesn't say much about the wider trajectory of the business.

Instead, management suggested that shareholders look at growth as compared to the prior quarter, which is impressive. "We are closely watching revenue trends for sequential stability," executives said, "and are quite pleased by what we're seeing thus far."

Wayfair is forecasting that second-quarter revenue will be higher than the $3.5 billion level the company notched in the first quarter, and adjusted earnings should be at or above this past quarter's level. Some head-turning demand swings are on the way over the next few weeks since consumers aren't likely to repeat their spiking preference for products in the home office niche as compared to the earliest phases of the pandemic.

But Wayfair should continue capturing more market share in the home furnishings industry, which is still growing quickly. Combined with rising profit margins, that's a formula for solid investor returns from here.