On global scale, Yahoo and Hotmail lead with 226 million and 222 million users. Google has 52 million Gmail users worldwide - ranking fourth according to ComScore Networks.
Sergey Brin thinks that the service would have some "significant financial benefits" one day. "We are spending an increasing proportion, but still a relatively small proportion of our engineering resources on boosting Gmail revenue". And he's right: after all, mail is the number one online activity, followed by search.
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