Baymard Institute once again provides a fantastic summary and findings from their in-depth research examining online grocery shopping. Several points stood out to me as unique departure from “traditional” online shopping:
1. Frequently or regularly purchased (e.g., “buy again” )
2. Ability to provide substitutions to sold out items
3. Delivery vs in-store pickup – sometimes in the same order
4. Ease of adding to card, often higher in the funnel than the traditional product detail page
Read the entire summary details here