This was 100% true of me as well for a decade or more. But getting into the Google Shopping Express beta changed everything. Same day delivery (i.e., even faster than Prime), competitive prices, up-to-the-minute order and delivery tracking, and sharply dressed and exceptionally polite and courteous couriers, means that for a large portion of "just use Amazon" products I'm now going with Google instead. See http://google.com/shopping/express/about/.
Selection and availability are of course the caveats of the early Google tests (limited to just San Francisco and parts of the Bay Area for now), and I was skeptical at first, but boy is this a game changer if we can pull it off. I've averaged almost an order a day since we started.
Granted, Amazon's use of OnTrac in San Francisco for Prime is also a factor. I may not renew my Prime membership for the first time since it launched as a result of OnTrac's poor service here.
(Ob. disclosure: I've worked at both companies.)