Amazon
Capitalization: $ 198 billion
Active users: 270 million
The cost of a user: $ 733
Alibaba
Active users: 350 million
The cost of a user: $ 621
Ebay
Active users: 152 million
The cost of a user: $ 474
Active users: 2 billion
The cost of a user: $ 182
Active users: 1.4 billion
The cost of a user: $ 158
Tencent
Active users: 2 billion
The cost of a user: $ 96

Active users: 302 million
The cost of a user: $ 81
Yahoo!

Active users: 600 million
The cost of a user: $ 70

Active users: 364 million
The cost of a user: $ 69
Groupon
Active users: 160 million
The cost of a user: $ 28
Zynga
Active users: 100 million
The cost of a user: $ 28
Yelp
Active users: 142 million
The cost of a user: $ 25
