Which Online Retailers Earn 3% with American Express Blue Cash Everyday Card?

American Express updated last year their no-fee Blue Cash Everyday card to offer 3% cashback on “U.S. Online Retailer purchases”, up to $6,000 per calendar year.

Please contribute any data points you have in the comments below on what counts to earn 3% cashback. You can follow along the comments to see what works, or you can use the Comments Search Bar (found directly above the comments) to look up a particular retailer. You can also check out a related thread we have for the Online Retailer category on the Bank of America Cash Rewards card.