The biggest advantage the tech giants have is their huge customer databases. While it is difficult to determine exactly how many customers each tech giant has, these numbers provide some perspective.
Google: According to Google, Google+ had 300 million monthly active users in October of 2013, up from 190 million in May. Google+ members who have interacted socially with any of Google’s services in the month of October 2013 totaled 540 million, up from 390 million earlier in the year.
Apple: Apple announced that they had over 800 million iTunes account holders in late 2013, most (but not all) of whom have credit cards on file.
Facebook: According to company reports, Facebook passed 1.19 billion monthly active users in late 2013. Of those, daily active users passed 728 million on average, and the number of monthly active mobile users hit 874 million. Facebook recently got an e-money license to offer financial services in Europe.
Amazon: It’s estimated that Amazon has close to 200 million active customers. Consumer Information Research Partners estimated that as of Q3 2013, Amazon ‘only’ had 41.3 million unique buyers in the United States. While a far cry from iTunes’ 800 million accounts, people spend a lot more on Amazon than they do on iTunes. Amazon also has credit card details from their clients.