Netflix Product Innovation Chief on the One Change That Increased Engagement By 200 Percent

Netflix is known to be a data driven company that relies heavily on A/B testing to create a personalised experience for its users, but you may not have realised that even the posters you launch the app are personalised for you. Take a look at your favourite shows on the Netflix interface on your TV, and then the next time when you're at a friend's place, and you may see a completely different image.

That's not because the poster was refreshed over time, but the reason is that the company actually personalises down to this degree in order to catch the viewer's eye, reveals Chris Jaffe, Netflix's Vice President of Product Innovation. Gadgets 360 caught up with Jaffe at an event taking place in Singapore last week where he told us about this, and other seemingly minuscule UI tweaks that all come together to keep the viewers engaged.

"What we realised [after the global rollout] is that people's taste isn't necessarily driven by demographic data," says Jaffe. "So my taste could have more in common with a granny in Japan, than with my neighbour in the US."

One of the ways in which this works is the posters you see. Netflix has a variety of different images, meant to highlight different aspects, whether it's the character in a Marvel show, or a more generic action poster look to be more appealing to action fans, or to highlight the conflict between people for drama fans, and each of these could be used to make the same show look more appealing to different people.

"Stories are actually very complex things and a show isn't just an action show, or a drama, there are lots of different elements, and our goal is to help you find something you want to watch," says Jaffe.

Netflix's Jaffe explains how the interface evolved

Netflix takes into account a number of different factors based on the content you've been watching to figure out what your interests are going to be, and using this, works out the different ways in which to tweak its interface. "We're heavily data driven, we don't just build things and launch them," says Jaffe. "We test them first with around a million viewers and see what the experience is like, before we roll the feature out. And more than half the things we test don't work."

One such change that generated controversy was the move away from the five-star rating system, towards simple thumbs up/ down feedback. Gesturing with his thumbs, Jaffe continues: "There was lots more engagement with [up, down gestures] - one to five stars is open to interpretation, while [up down] is much clearer. And we saw a 200 percent increase in engagement when we switched, and that continues."

Another change - which wasn't too successful at first, but was brought back later after tests were more favourable - was having TV shows play clips instead of just displaying a large static image when selected.

"TV has always been about video, so it was very appropriate to the context, unlike on mobile," says Jaffe. "When we got on to TV, the interface," he pauses to show a picture of the original Netflix TV interface, "wasn't really great. There was too much going on, it was too bright. So it took us a little time to optimise for remotes, get the colours right, the borders, we kept testing and improving."

"We called it the efficient vending machine," he says, "getting you to watch something - " he pauses again and corrects himself, "getting you to something that you want to watch, quickly."

Disclosure: Netflix sponsored the correspondent's flights and hotel for the event in Singapore.