Investors will look for signs that Amazon's aggressive expansion of same-day delivery services helped increase its third-quarter profit margin by spurring shoppers to place more frequent and bigger orders. Same-day delivery is now offered in at least 90 cities, free for Prime members while non-members pay $9.99. The retailer invested heavily in 2020 and 2021 in logistics to make same-day delivery, which it introduced in 2015, available in more places.