Should Investors Be Concerned That Amazon Didn't Disclose Prime Metrics?

Should investors be worried that Amazon.com, Inc. AMZN didn't disclose the growth rate of Prime members in 2016?

According to calculations conducted by Recode's Jason Del Rey, Amazon boasted at least 46 million Prime members this time last year. Fast forward to today and the company has since added "tens of millions" of net new additions, which brings its total to 66 million.

While this is by any account a large number, Del Rey pointed out that Amazon's earnings report failed to mention the annual growth rate of Prime memberships for the first time in years. Specifically, Amazon disclosed that its Prime membership in 2014 grew 53 percent, followed by a 51 percent growth rate in 2015.

With that said it's unclear what exactly Amazon's growth rate was in 2016. The reporter reached out to Amazon for clarity since he argued "Amazon doesn't disclose, or withhold, any numbers by accident" but has yet to receive a response.

The working assumption for the time being is that Prime membership growth slowed down at a faster rate compared to prior years. Granted, Amazon can't grow its Prime membership indefinitely and the market needs to reach saturation at some point.

Prime members also spend more money than non-Prime members so maybe investors are reading to much into the lack of a growth rate disclosure.

"But if Amazon is worried enough about the perception to not reveal the number, it's worth noting," Del Rey concluded. "Noted."