The supplier delivered revenue of $40.6m to its clients last month, up 269% from 2018.
GAN attributed the rise in revenue to the high demand for internet gambling in both New Jersey and Pennsylvania, following the launch of the NFL season in September.
Performance was also improved by the cross-selling of online sports bettors to online casino gaming in both states.
Last month, the supplier also launched in Indiana after expanding its deal with FanDuel.
GAN’s Q3 results were released last month, showing revenue growth of 203% to $80.9m and a rise in active player days to $5.4m, an increase of 59%.
Dermot Smurfit, GAN CEO, said: "We are pleased the ramp up in real money internet gambling is accelerating ahead of our budgeted expectations in Pennsylvania and New Jersey, particularly since the start of the American football season in early September.
"Given the rapid increase in the total addressable market for the US internet gambling operators and their infrastructure providers such as GAN, we expect to see continued and rapid growth."
