Ann: Cash Revenue Guidance - December 2017 Quarter, page-80

Just a quick calculation, looks like we have 1500 paying US customers so far. Based on previous info, US customers spending AVPU US$5000 = roughly AU$6000.
Thats pretty decent growth in a short time.
In September the company announced that over 2 quarters, q3/q4 2017, the company generated US$6 mil in annualized contract value. That would be US$1.5mil = roughly $2mil AUD. So about $1mil AUD a qtr.
So US has grown about 140% in 6mths. It would be reasonable to assume it will explode soon with the Zeta deal.