Amazon's record profits last quarter would've been impossible without an accounting change and a huge spending cut. That raises questions about future earnings growth. (AMZN)

· Amazon saved nearly $2.6 billion in net profits last quarter by cutting its marketing spend and through a previously announced estimate change for its server costs.
· The change is noteworthy given how Amazon's net profit doubled to a record $2.6 billion last quarter, and shows how the company boosted its profitability in...