Amazon's third-quarter earnings beat Street estimates, but its revenue and fourth-quarter outlook fell short of expectations, causing the stock to plunge in extended trading.

Here are the most important numbers:

EPS: $5.75 vs. $3.14 estimated, according to Refinitiv

$5.75 vs. $3.14 estimated, according to Refinitiv Revenue: $56.6 billion vs. $57.10 billion estimated, according to Refinitiv

$56.6 billion vs. $57.10 billion estimated, according to Refinitiv AWS revenue: $6.68 billion vs. $6.71 billion estimated, according to FactSet

The company gave fourth-quarter revenue guidance in the range of $66.5 billion and $72.5 billion, well-below consensus of $73.79 billion. The fourth quarter is the biggest and most important sales period for Amazon because of the holidays.

Amazon shares plunged 10 percent in premarket trading Friday to $1,600 a share. At this rate, it will be the stock's biggest decline since an 11 percent drop in January 2014.

The results show how Amazon could have a disappointing holiday season in its all-important fourth-quarter, as the overall business sees a slight deceleration in growth. At the same time, it highlights the growth of Amazon's high-margin businesses, like its cloud and advertising units, that are more profitable than its core retail segment.

Its fourth-quarter operating income guidance of $2.1 billion to $3.6 billion was also below Street expectations of $3.9 billion. Amazon said the wage increase announced earlier this month was incorporated into the guidance, but declined to quantify its impact.