Nothingness: Note also that if you move 10 times a day, and your opponent moves one hour after you move, your opponent is a faster player than you. Out of a 24 hour day, it's your opponents turn 10 hours, which means, for 14 hours, it's your turn. On average, he moves faster.

Considering time zones, people needing sleep, and the unreliability of the internet, I'd say that anyone picking a time control of less than 24h/move on average takes a risk. And I've no sympathy if they lose a game because their clock runs out.