This excerpt taken from the AMZN 10-K filed Feb 17, 2006.
As of January 1, 2005, we adopted SFAS No. 123(R) using the modified prospective method, which requires measurement of compensation cost for all stock-based awards at fair value on date of grant and recognition of compensation over the service period for awards expected to vest. The adoption of SFAS 123(R) resulted in a cumulative benefit from accounting change of $26 million, which reflects the net cumulative impact of estimating future forfeitures in the determination of period expense, rather than recording forfeitures when they occur as previously permitted. See Note 1Description of Business and Accounting PoliciesStock-based Compensation.
This excerpt taken from the AMZN 10-K filed Mar 11, 2005.
Effective January 1, 2002, we prospectively changed our inventory costing method from the specific identification method to the first-in-first-out (FIFO) method of accounting. This change resulted in a cumulative increase in inventory of $0.8 million, with a corresponding amount recorded to Cumulative effect of change in accounting principle on the consolidated statements of operations. We received a letter of preferability for this change in inventory costing from our independent auditors.