The key is 100% boycotting all services provided by a company. Wikipedia’s list of Amazon product/services as reference (https://en.wikipedia.org/wiki/List_of_Amazon_products_and_services).
Incidentally, I know entire neighborhoods that don’t have other grocery stores besides Target/Whole Foods, not to mention that AWS is the cloud computing industry standard… As a personal example, my vet-prescribed cat foods are manufactured by Purina, a subsidary of Nestlé (needless to say, a separate but also extremely evil large corporation)
The most plausible way is a short-term boycott for like 2 weeks at the end of their fiscal reporting period. You want the rebound not to be reflected in the quarterly report so it fucks with the share prices.