Maybe you know the feeling. You’re scrolling around on Amazon Prime Video, minding your own business, and you stumble upon the perfect Saturday night movie. But when you go to click on it, you realize—wait a tick—it’s only available to rent or buy.

In other words, Amazon is asking you, the person who already pays for a Prime Video membership, to pay even more money to watch a sappy romantic comedy (no judgment) that you never would have actively sought out.

Well, if you’ve ever experienced that bait-and-switch sensation, you have plenty of company. In fact, almost 30% of the most popular titles on Amazon Prime Video aren’t actually included in a Prime Video membership, according to a new report from analyst firm MoffettNathanson.

The firm, with help from third-party market researchers, looked at polling data from almost 19,000 streaming TV viewers to determine which shows and movies were the most popular on Amazon’s popular streaming platform. The top show, not surprisingly, was the Emmy-winning Marvelous Mrs. Maisel, with just over 10% of respondents citing it as their favorite. Tom Clancy’s Jack Ryan was No. 2, followed by The Boys. About 5% of respondents cited movies, The Office, or Friends as their favorite title on Amazon.

Generally speaking, Amazon Prime Video has a “growing content problem,” the report says, because only 20 of its top 100 titles are original, while more than half of them are acquired from somewhere else.

But 28 of those titles are what MoffettNathanson describes as “not on service,” which suggests a “high level of brand confusion when it comes to streaming content,” according to the firm.

“To clarify, most of the ‘not on service’ shows are available for purchase on Amazon, but are not included with a Prime Video membership,” the analysts wrote. “So, consumers are confusing the streaming service for the Amazon video store.”