DraftKings (DKNG -3.77%) benefited from a rebounding sports calendar to post significant sales growth through late September. The sports betting specialist on Friday revealed that revenue jumped 98% year over year in the fiscal third quarter.

Much of that gain came from its acquisition of the Diamond Eagle business, but sales still rose 42% after adjusting for that purchase.

Executives credited the restarting of the professional sports calendar for helping push DraftKings' pool of active users up 64% to over 1 million. "The resumption of major sports such as the NBA, MLB, and the NHL in the third quarter generated tremendous customer engagement," CEO Jason Robins said in a press release. 

A man makes a sports bet on his smartphone.

Image source: Getty Images.

Investors have been growing more optimistic that increased sports betting access would help lift DraftKings' business even as the sporting calendar allows for a wider range of betting activity. Executives cited both those favorable trends as they boosted their short-term outlook.

DraftKings now sees sales rising to between $540 million and $560 million this year, equating to organic gains of between 25% and 30%. Management's previous outlook had predicted revenue between $500 million and $540 million. The company also introduced a 2021 forecast that called for a further 45% sales boost next year that would push its annual sales base to between $750 million and $850 million. That forecast involves several major assumptions, including no further disruption to the sports calendar from the COVID-19 pandemic.