AP
After Amazon announced that it would have a Black-Friday-style sale for Prime members on July 15, Wal-Mart countered by offering its own shopping event - starting on the same day - with thousands of online-exclusive discounts.
In announcing its sale, Wal-Mart chided Amazon for making "Prime Day" available only to Prime members, who pay $99 a year for free two-day shipping and other perks.
Amazon responded by accusing Wal-Mart of charging customers higher prices in stores than they do online.
But how do Wal-Mart and Amazon really stack up next to one another?
Here's a brief breakdown of the two companies and how they compare from the internet marketing company WebpageFX.
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.