redletterdave writes: "After several years of dominance, Microsoft's Web-based email service, Hotmail, has been unseated by Google's significantly younger webmail service, Gmail. Google announced it had about 350 million monthly active users in January; since then, that number has ballooned to 425 million." Link to Original Source
Computers are unreliable, but humans are even more unreliable.
Any system which depends on human reliability is unreliable.