About 22% of cable subscribers also subscribe to an over-the top service, according to a new study.

Research company Millward Brown Digital says that while some cable customers cut the cord while going over the top, others are content junkies that have robust TV subscriptions in addition to getting OTT content.

While Netflix is the biggest OTT provider, Millward Brown Digital says that HBO, which introduced HBO Now in the second quarter, is recording the fastest growth. Amazon Instant Video is also growing faster then Netflix, possibly because of the strength of Amazon Prime. Hulu, which recently announced an ad-free tier, has been growing more slowly the last few quarters.

Most of the subscribers to HBO and Netflix are milllenials, according to the study, with 54% of HBO’s over-the-top subscribers falling into that young category. For Amazon, only 42% of their subscribers are millennials. For comparison, 35% of cable login subscribers are millennials. Baby boomers comprise 25% of cable subs.

“It’s important to note that these insights do not declare the death of cable TV. Rather, they highlight the importance of content to a cable provider’s overall strategy and the importance of targeting that content to different generations,” Millward Brown said.

“As consumer preferences for content consumption continues to evolve, Internet service providers, over-the-top device manufacturers and content providers need to evolve with them Understanding the current landscape is the first step in being able to quantify the impact of content everywhere on their business, align their marketing strategies to complement how consumers make decisions today, and identify the role content decision play in the overall consumer journey," the company said.