Not only that, Google apparently has agreements with mobile network operators to ensure that their long-lived connections don't get closed after a few seconds o

Not only that, Google apparently has agreements with mobile network operators to ensure that their long-lived connections don't get closed after a few seconds or minutes of inactivity. Some mobile ISPs close idle connections after as little as ten seconds, so unless you're in a position to negotiate with just about every major mobile network operator worldwide, you can't really offer the same level of service.