Ecommerce sales in the US grew by 18% per year between 2019 and 2023 driven by the brutal impact of Covid, according to an analysis by McKinsey. For the coming years, the growth rate is expected to 'normalise' around a more modest, but still good 6% per year. The cost of delivery is considered the most important factor by consumers. speed remained a key factor, but many consumers are prepared to wait up to 3 days (tending to be no longer) to receive their parcel. Increasingly important instead is flexibility in delivery and ease of return.