The strategy: Even as Amazon’s retail business continues to gain share of online sales worldwide, there’s still ample room for growth since roughly 80% of global retail sales occur in physical stores (our forecast expects that share to be 79.2% this year), CEO Andy Jassy noted in his annual letter to shareholders.

The details: The letter mapped out a few key retail-focused growth levers:

Faster fulfillment: Amazon is taking several approaches to compress delivery times, including using more than 1 million robots in fulfillment centers to drive efficiencies and improve worker safety. It has also developed more than 85 Same-Day Fulfillment Centers, is testing “Amazon Now,” a 20-minute delivery service powered by micro-fulfillment centers, and continues to pursue its Prime Air drone delivery service, which it expects will deliver 500,000 packages annually by the end of the decade. Amazon is running each initiative in parallel to serve different use cases and push delivery speeds faster.

Faster rural delivery: Amazon is investing $4 billion to expand its rural delivery network, aiming to cut delivery times from four days to one in some areas. The company believes the investment will make Prime membership more compelling and reshape how consumers—especially in underserved regions—perceive its value. That push comes as Amazon’s retail ecommerce sales are projected to top $1 trillion by 2028.

Grocery as a major growth engine: Amazon’s decision to fold perishable groceries into same-day delivery last year has been a “big breakthrough,” Jassy wrote, noting that perishables sales grew more than 40 times last year and now account for nine of the top 10 most-ordered items in same-day delivery where available. The retailer—which closed its remaining Amazon Fresh and Amazon Go locations earlier this year—hasn’t lost interest in brick-and-mortar: It plans to open at least 100 Whole Foods locations and is experimenting with larger-format stores.