NEW YORK (BLOOMBERG) - Netflix is not blind to the competition but says it does not consider HBO a prime threat.

HBO is often touted as one of the streaming service's biggest foes.

Both companies are vying for TV subscribers, and are frequent rivals in award competitions, including the Emmys.

But according to Netflix, HBO is less of a threat than a video game: Fortnite.

"We compete with (and lose to) Fortnite more than HBO," Netflix said in a letter to shareholders on Thursday (Jan 17).

The free-to-play game may have raked in as much as US$2.4 billion (S$3.3 billion) in sales last year, more than any 2018 Hollywood blockbuster, with revenue from selling items such as character skins and battle passes.

On Thursday, Netflix also revealed that its programming now accounts for about 10 per cent of television screen time in the United States while total paid streaming subscribers has reached 139 million worldwide.

It also estimated that 80 million households would have watched its Bird Box movie, starring Sandra Bullock, in its first four weeks, after it was rolled out in the middle of December.

That show prompted a wave of copycats doing tasks blindfolded, as Bullock's character does to ward off an evil being.