Paddy Power-Betfair is targeting so-called 'contribution' profits of $600m (€530m)from its currently loss-making US operations by the middle of the next decade.
Similar to gross profit, contribution profits ignore a raft of business overheads - such as operating and administration costs, sales and marketing costs and R&D.
But, even after these are accounted for the US earnings could amount to around $350m by 2025, putting that division of the group on a par with its online business.
The betting and gaming services group last month reported a £15m (€17m) loss from its US business, which analysts expect to remain loss-making until around 2023.
Paddy Power-Betfair's American business includes a New Jersey-based online casino product, the TVG online horseracing outlet and two fantasy sports businesses Draft and FanDuel.
The group owns 58% of the latter, but has the option to buy up to 95% either through cash or equity.
Paddy Power-Betfair said its US forecasts - which were unveiled to analysts at a recent investor day in New Jersey - are based on a modest regulatory outcome, whereby it would control roughly 20% of a market open in between 12 and 24 states.
"We caution that the key driver of the US opportunity will be the pace of market regulation," said Davy analyst Michael Mitchell.
"However, should the market evolve even along the lines set out by the cmopany, we see few reasons why it could not achieve this aim," he said.
"Already the leading online sports and gaming operator in the US, it has a well-invested platform to support its growth ambitions. Coupled with its strong start in New Jersey, the company appears to be uniquely positioned as the US sports betting market launches," said Mr Mitchell.
The investor day reinforced out initial view that the US opportunity is exciting and potentially very valuable for the group.
Crucially, Paddy Power's US growth will be organic, with no more acquisitions planned and the potential to buy the bulk of the remainder of FanDuel with stock.
Last month, when the business reported a 9% increase in overall 2018 group revenue but an 11% drop in pre-tax profits, management said it would be looking to enter more new markets in mainland Europe via bolt-on acquisitions.
However, it said it is comfortable in its core markets of Ireland, the UK and Australia and is only likely to grow organically in the US.
In February, Paddy Power acquired a controlling stake in Georgian online betting firm Adjarabet for €115m.