Profits for the company's third quarter rose 8% and the rise of BT Sport customers attributed to the brand's 6% revenue growth in the consumer business.
BT Sport launched in May last year, promising an "affordable and exciting" new service for consumers that would challenge the dominance of Sky Sports.
Chief executive Gavin Patterson said the company achieved some "particularly strong" audience figures in December, while winning the exclusive rights to the UEFA Champions League and UEFA Europa League will strengthen the appeal of BT's proposition.
BT outbid ITV and BSkyB to win the exclusive live broadcast rights for all 350 matches in November last year, in a £900m deal.
Yesterday Patterson urged marketers to "keep fighting the good fight" in the face of a bashing by the Labour Party, while speaking at the Advertising Association's Lead Conference.
He said: "We [the marketing industry] are a lightning rod for an array of social issues and are used to score political points.
"Leadership in advertising is crucial to the vitality of our economy and society. Our instinct told us advertising was central to the economy and we’ve backed that with 'Advertising Pays'."