It's a synthetic number. From the article: "We don't disclose exactly what we pay for transit, but I can give you a relative sense of regional differences. To

It's a synthetic number. From the article: "We don't disclose exactly what we pay for transit, but I can give you a relative sense of regional differences. To start, let's assume as a benchmark in North America you'd pay a blended average across all the transit providers of $10/Mbps (megabit per second per month). In reality, we pay less than that, but it can serve as a benchmark, and keep the numbers round as we compare regions."