Amazon has played a prominent role in the structural shift away from brick-and-mortar retail, and it may lay waste to several other retailers in the years to come. Without the cost burden of physical stores, Amazon can price below traditional rivals and drive recurring traffic online. Even with the threat of online sales tax collection, we believe Amazon can maintain its value proposition through other means, including adjustments to shipping policies or Amazon Prime. Aided by the network effect inherent in 250 million active users and recent fulfilment infrastructure, technology, and content investments, Amazon owns one of the wider economic moats in the consumer sector and will likely remain a disruptive force within the retail, digital media, and cloud computing categories.
Amazon's growth potential is undeniable. Key top-line metrics, including active users (which have grown at a 22% CAGR the past five years), total physical and digital units sold (38% CAGR), and third-party units sold (48% CAGR) continue to outpace global e-commerce trends, suggesting that Amazon is gaining market share while fortifying its network effect. Nevertheless, based on operating margins of 1.0% in 2013 (2.7% excluding stock-based compensation and amortization of intangibles), our fair value estimate seemingly requires a leap of faith based on whether the company will be able to monetize its explosive growth.
Marketplaces innovations and an expanded portfolio of payment technologies have reshaped eBay into a major commerce hub. Amazon may hold the title of top destination for U.S. online shoppers, but we believe eBay will remain relevant in the years to come because of its desire to partner, not compete, with other merchants, and enable them to compete in the rapidly converging world of online, offline, and mobile commerce.
In our view, the market has underestimated eBay's broad-based potential as a commerce facilitator, the result of search engine and website enhancements, increased free and same-day shipping options, and store-level merchant tools. We also find eBay Enterprises' fulfilment, warehouse, payment, freight, and customer service offerings compelling, while mobile applications, payment services, and in-store PayPal tests provide longer-term growth optionality. Marketplaces' gross merchandise volume trends have recently come under pressure because of disruptions from a May 2014 data breach and changes to Google's search algorithm. We believe management took appropriate measures to protect its network effect--the primary source of our wide moat rating--in asking Marketplaces users to change passwords after the data breach, even if it comes at the expense of near-term user engagement and profitability.
Our positive long-term outlook is further validated by recent PayPal and Marketplaces active user growth, and resilient margins despite customer experience and engagement, cross-border, local merchant, and PayPal investments. We're also intrigued by eBay's exposure to mobile commerce, and estimate that around 40% of new Marketplaces and PayPal users in 2013 came from mobile devices. Many of these mobile users are younger customers with lower disposable incomes, often from emerging markets, but also a lifetime of potential transactions ahead.
These stocks were identified as undervalued with an economic moat using the search function in Morningstar Select