Not to mention the video someone posted beloew from an engineer talking about Erlang there in 2014 has some interesting numbers. Christmas/New years is peak, and on Christmas Eve they were maxing out at 146GB/s out.

If we assume they maybe averages 75% of that over 6 hours, that's 146Gb/s * (60606)s / 8bytes/byte * 0.75 * 0.05dolars/GB = $14,782.50 for a 6 hour period (estimate).

That's highest listed bandwidth tier price for Azure, I'm sure they would pay less for a number of reasons. But let's just say that $10k for a whole day may not be out of the realm of possibility. That puts bandwidth costs possibly North of $3 million a year. Even at $1 million, that's a lot of money.