There are a few problems with the very simplistic statistics in this article: 1) These stats don't account for growth in employee base. If a company is growing

There are a few problems with the very simplistic statistics in this article: 1) These stats don't account for growth in employee base. If a company is growing their employee base by hiring new employees they could have 0% attrition and the average duration of employment would still be low simply because of all the new employees that just started. 2) Most of these companies have a lot of different roles. For Amazon they obviously have fulfillment center employees working in the warehouses, folks working in the data centers, and folks doing engineering. I suspect these roles have very different attrition rates. The same goes for Apple, Facebook, etc. You could have 0% attrition rate on your core engineering team but still have a low average average employee "age" because there is high turnover in your customer support call center. Basically the simplistic stats in this article are absolutely worthless and not newsworthy, which unfortunately is pretty par for the course with Business Insider.