All the examples you have quoted are examples of parallax sites which use shifting content to tell and story and keep the user engaged.I am going to break this response into three parts.
I would recommend looking at this article for additional inputs on how parallax sites keep users engaged.
Parallax scrolling offers the ideal setting to tell your story in an
engaging and interactive way. Let your visitors take control and let
them walk through your story in their own pace. The different layers
that respond differently to the scrolling behaviour of your visitors
create a sense of depth and even allow for multiple story lines.
Make your visitors curious
The drink Michelberger Booze engages you as a visitor in a very
creative way. At the very top of the site it says: “Just scroll down
gently… When your glass is empty, click to feel the booze.” What is
the booze? When scrolling down the page, you see an artistic still
life setting. When scrolling further, two things happen. The watch
hands rotate and the drink disappears. Then a mask appears which, when
clicking on it, leads you to the booze — a beautiful, animated
illustration that represents the sphere of the drink. Only at the very
end of the site, you get the actual information about the drink.
Still, there is almost no way to get there without engaging with the
Let your visitors have some fun
Another great example of how to engage your visitors is the site of
the KRYSTALRAE fall collection. Different outfits are presented on one
and the same model. The design is very minimalistic, focussing all
attention on the model and the dog in the center of the page. When
scrolling down the page, you can change the outfit yourself, while the
rest of the scene stays the same. This interaction is simple, but fun
and very engaging.
Surprise your visitors
You can also use parallax scrolling to surprise your visitors. For
example, on the Japanese website of the Nissan Note, you get an entire
story about the car, when scrolling down the page. This already makes
it a special experience. However, once you are at the bottom of the
site, there is a link that says: “Try Reverse!” The site automatically
scrolls back to the top, giving you yet another version of the story.
That said,there is no concrete information which shows that a simple site vs a parallax site would perform poorer except for this study which showed that the user journey was similar for users on both sites except they found these parallax scrolling sites to be more fun :
So Frederick set up a study of his own. He designed two hotel
websites similar in every way, from content to color scheme, except
that one featured parallax scrolling and one did not. Frederick then
intercepted 86 people in the lobby of the Stewart Center, a main
gathering point on Purdue's campus, and brought them to a computer
where they engaged with either the standard site or the parallax site
The test itself didn't last very long. Participants spent a few
minutes getting familiar with whichever site they'd been assigned.
They entered demographic information into a web form. (They all
experienced a site error, too, because Frederick wanted to incorporate
the unruly nature of web use.) They made a hotel reservation. Finally
they rated the site on a questionnaire crafted from prior web
Frederick's survey focused on five areas of the user experience:
usability, enjoyment, fun, satisfaction, and visual appeal. (Enjoyment
and fun, while ostensibly similar metrics, differed in that a site
like IMDb can be enjoyable without being fun in the way a video game
site might be.) Before he tallied the results, Frederick was convinced
the parallax site would blow its opponent away.
"I've read from many blogs how people say it's going to attract users
and create so much of a better user experience," Frederick tells
Co.Design. "I thought it was going to be superior to a typical website
in every aspect."
As it happens, the parallax site was only superior in one
sense--fun. None of the other survey measures indicated a
significant difference in user experience between the two sites.
Parallax didn't even edge the standard site in questions about visual
appeal (although participants did think it looked slightly more
"professional"). Frederick also discovered one critical disadvantage
of parallax: test participants who suffered from motion sickness found
the style disorienting.
- Do people really read the content on these kinds of pages? - There is no comprehensive data on this but the higher levels of engagement would perhaps ensure the users do go through all the content
- How does it fare when compared to a static page that tries to drive the same point? - As per the above mentioned study, there is not much difference in conversion, but there are obviously higher levels of engagement
- Does it have any advantages over 'traditional' homepages? - Higher levels of engagement and potentially higher levels of conversion.