The online retailer captured 53% of online sales growth in the U.S., according to new data from Slice Intelligence. Amazon’s e-commerce success is up from 40% in 2015, the Slice report said, a time when the company also accounted for 43% of all online revenue.

Electronics like Amazon Echo and other products have helped the company grow significantly, while the company also managed to stay on top thanks to its shipping speed, Slice found. As of December, Amazon packages delivered in an average of 3.4 days, beating out the average of 5.6 delivery days from other online services.

“Amazon maintains an obsessive focus on removing every pain point from the buying process. This is clearly exemplified with its Prime program, with free, reliably quick shipping,” Slice principal analyst Ken Cassar wrote in a blog post. “While the rest of the market is investing to get our packages to us faster, Amazon still maintains a significant lead.”