Nonstore sales, which are mainly online sales, reached $55.08 billion in February, according to the Department of Commerce.

U.S. nonstore sales grew steadily in February, new monthly data from the U.S. Commerce Department shows.

What the agency calls “nonstore sales” reached $55.08 billion in February on a seasonally adjusted basis, a 10.1% increase compared with $50.01 billion in the same month of 2017. That’s about the same year-over-year increase as January, when nonstore sales increased 10.2%.

Nonstore sales mainly take place online but also include other channels such as mail and telephone orders, door-to-door sales and sales through vending machines.

Internet Retailer uses the monthly nonstore figures disclosed by the Commerce Department as an early indicator of the health of the e-commerce market. The Commerce Department only reports e-commerce sales on a quarterly basis. The agency will release its first-quarter results on May 17.

A historical look at the correlation between nonstore sales and e-commerce sales show that e-commerce is a growing portion of nonstore sales. In the fourth quarter of 2017, for example, e-commerce represented 73.3% of nonstore sales, an Internet Retailer analysis shows. That’s compared with 69.2% for Q4 2016.

Using those same percentages, this would suggest that in February, e-commerce sales reached roughly $40.37 billion, compared with $34.60 billion a year earlier. An increase of 16.6%

Total retail sales reached $492.01 billion in February on an adjusted basis, up 4% from $473.11 billion in February of last year. In January, total retail sales increased about the same amount year over year to reach $492.34 billion compared with $474.03 billion a year earlier.