One of the best credit cards to use for online purchases is the Citi AT&T Access More card (unfortunately this card has been discontinued). This card earns 3x Thank You points for online purchases, however, I have not seen a good list for what retailers qualify for the 3x points. I am going to keep my own list of sites that qualify and when those transactions occurred.
List of Citi AT&T 3x Online Retailers
|Dunkin’ Donuts Mobile App||1/7/19|