[equil]

Quite the opposite, actually. http://i.imgur.com/bKBcIyX.jpg [1]

[1] https://design.google.com/articles/evolving-the-google-ident...

[amelius]

Yes, I said "optical" spacing. Not real spacing.

The link you provide is interesting. However, any technical explanation doesn't solve the optical illusion that the last three letters appear to be closer together than the first three letters.

[kuschku]

Yes – that’s why normally you use serif fonts and modify the width of the strokes dynamically. Also the reason why the old 'o's were tilted.