WASHINGTON — The nation’s largest retailers have collectively held their top spots thanks to one common denominator: rethinking merchandise offerings while enhancing their omnichannel efforts. This is one of the findings from an annual ranking of U.S. retailers by domestic sales compiled by the National Retail Federation and Kantar Retail.

According to the findings, retail’s balance of power resides in the hands of the consumer. Merchants who embrace this ongoing shift are poised to recast the future as well as lead retail’s digital transformation.

Most of the retailers in the top 10 have held such rankings for several years due to their ability to connect with savvy customers. These retail leaders have embraced a wide range of omnichannel strategies that have transformed the retail experience with such options as buy online with curbside pickup, direct-to-customer fulfillment, same-day shipping, and personalized and mobile shopping.

This year’s assessment notes growth in specialized niches with few head-to-head rivals or with fragmented competition from smaller regional chains. For example, 71st-ranked Tractor Supply Co., which has about 1,500 stores, began the year with a 10.2% sales increase in the first quarter.

Longtime top-100 stalwart PetSmart Inc. is a strong player in a segment that was driven by a rising demand for senior, weight management and special needs pet products and had sales that approached $4 billion last year, says the report.

In the supermarket sector, Aldi, the German-owned limited-assortment grocer, jumped from No. 36 last year to No. 19, an advancement that knocked Texas-based grocer H-E-B out of the top 20.

Other noticeable changes in this list are the success of dollar stores. Revenues in this niche segment have grown fast, and the acquisition of Family Dollar Stores Inc. by Dollar Tree Inc. positions Dollar Tree for additional growth as customers’ desire for convenience and low prices shows no signs of waning.

“Shoppers today are looking for stress-free shopping experiences,” Kantar Retail senior vice president Mary Brett Whitfield said. “Most of the retail operators in both the top 10 and the rapid climbers in the top 100 are innovating in ways that allow shoppers to simplify and streamline shopping routines.

“These efforts, as well as continuing to seek deeper shopper engagement across all connection points, are key to growth and success.”