Amazon Web Services recorded a 69 percent jump in revenue for its fourth quarter to bring in US$2.4 billion (A$3.4 billion), taking sales for the full 2015 year to almost US$8 billion.
The growth rate was, however, slower than in previous quarters - AWS posted 78 percent growth in the third quarter and 82 percent in the second quarter of 2015.
The cloud unit of Amazon brought in US$687 million in operating income for the quarter - compared to US$240 million one year earlier - and US$1.86 billion in operating income for the year, compared to US$660 million in 2014.
Sales for the full year hit US$7.88 billion compared to US$4.6 billion the year prior.
The results mark just the fourth time Amazon has broken out the financial performance of its cloud computing business.
Overall, Amazon missed both earnings and revenue expectations and its stock fell as much as 14 percent following the results announcement.
Sales for the fourth quarter grew 22 percent to US$35.7 billion, and for the full year jumped 20 percent to US$107 billion.
Net income for the fourth quarter reached US$482 million, compared to US$214 million the quarter prior, and for the full year hit US$596 million, compared to a net loss of US$241 million in 2014.