It makes sense for the phenomenon to be so widespread: after all, why would two roommates or family members or even good friends have separate video streaming accounts when they can share a subscription? But, this 'mooching' phenomenon can eat into subscriber growth and profit.

The password-sharing number, from a USA Today poll, dovetails with a recent survey from Parks Associates that found such credential-sharing costs over-the-top (OTT) providers $500 million in revenue this year.

Parks found that 6% of US broadband households use an OTT video service that is paid by a person living outside of the household, but that number increases among millennials: 20% of OTT users aged 18-24 use an OTT video service paid by someone outside the home, the highest of any age group. Only 10% of OTT subscribers 25-34 admit to this behaviour.

Glenn Hower, research analyst at Parks Associates, commented: "Credential-sharing has a measurable impact on video services, particularly in the OTT video service area, where young subscribers are active. The impact on OTT video revenues is especially troublesome as OTT providers are investing large sums of money to boost their original content offerings."

From the article "Over a third share HBO NOW, other streaming passwords" by Michelle Clancy.