Lies, damned lies, and US government statements
According to the US government, as of September 2014, Silk Road 2.0 was generating sales of at least approximately $8m (£5.3m) per month
"Generating sales"? Sounds to me like the US government are using the total value of all transactions, and implying that amount was how much SR2.0 was making.
Somewhat like saying Mastercard "generated sales" of $300gzn last month, when what they actually did was enable third-party transactions of that value, and take but a small cut of that large amount.