Piper, after streaming a few episodes of "Marco Polo." Ursula Coyote for Netflix The most popular original shows on Netflix are "Orange is the New Black," "House of Cards," "Arrested Development," "Marvel's Daredevil," and "Unbreakable Kimmy Schmidt."

At least, that's according to a recent survey from from RBC Capital Markets.

Analysts and investors have to rely on third-party data like this, do a lot of guesswork, and decrypt the occasional statement from Netflix executives, to figure out roughly how many people actually watch the shows and movies available on the streaming service.

Netflix has long said that because it doesn't rely on advertising, it really has no reason to share any sort of viewership metrics.

But Mark Mahaney, an analyst at RBC, sends out a survey each quarter to more than 1,000 US internet users, and one of the questions it asks is which of the service's original shows have respondents watched.

Here's the results of that survey. The pink bars reflect the percentage of respondents to the most recent survey who reported watching a particular series. The other bars show how respondents replied in previous surveys:

RBC Capital Markets

57% of respondents to the most recent survey said they've watched "Orange," while 45% said they've watched the political thriller "House of Cards." 29% reported they've watched "Arrested Development," 23% said they viewed Marvel's "Daredevil," while 22% responded that they've watched "Unbreakable Kimmy Schmidt."

As Mahaney writes in the note accompanying this chart, the viewership of "Kimmy Schmidt" and "Daredevil" are particularly strong considering those series (which are both worth watching) were released in March and April, respectively.

13% of people reported they had watched "Marco Polo," a series that has been panned by critics but which Netflix reportedly spent $90 million on for one season. 11% of respondents said they watched "Lilyhammer," the drama that was canceled last month.

Only 9% reported they watched "Bojack Horseman," the cartoon that stars the voice of pretty much everyone.

There are horses that drive in the Netflix original "Bojack Horseman." Netflix As Re/code's Peter Kafka writes, this data is far from perfect, as it doesn't give us the completion rate for the shows. Just because 57% of people watched at least an episode of "Orange," for example, doesn't mean that anywhere near that number watched the entire season.

I was particularly surprised by the relatively high proportion of people who reported watching "Arrested Development," though it's unclear which season of the show the respondents actually watched. Only the fourth season is a Netflix original, while the first three (which many people argue are better) first aired on Fox.

Netflix is spending hundreds of millions of dollars this year on original programming, investing in it to differentiate itself from increased competition, as well as make the service attractive to people outside of the US. Netflix, which is currently available in more than 50 countries, has said that its goal is to operate in every country in the world by the end of next year.

There are more options than ever to watch TV without actually paying for a cable or satellite subscription and renting expensive hardware each month, and more Americans are choosing to ditch their traditional TV subscriptions in favor of streaming.

HBO and Showtime have both recently launched standalone streaming services, and Amazon and Hulu continue to beef up their services to compete.