Google made $74 billion last year. And it wasn’t from painting weird dog montages or winning a few matches of Go . A vast majority of Google’s revenue is from advertisements slipped into its free services like Search and YouTube. That’s why AdWords is really Google’s most important product, as it allows a million different businesses, big and small, to manage keyword-driven ad campaigns across Google.

But for all its importance, AdWords hasn’t seen a facelift in eight years. That changes today, as Google unrolls a new design to select AdWords customers, as part of a carefully paced, year-long makeover of the platform to conclude in 2017. The new AdWords will incorporate Material Design–Google’s modern design language that’s already being used across its other services–and it prioritizes clean graphical insights over lists of text and numbers.

Updating AdWords will not only cement Google’s design makeover across its most important services; it will also make its platform a whole lot more usable in a time when advertising campaigns have grown more complicated than ever.

“AdWords started with 350 customers 15 years ago . . . [then] it was rewritten 8 years ago as search advertising became really important for marketers. But it was built for a desktop search world,” says Greg Rosenberg, head of UX, advertiser platform at Google. “Today, we’re in the middle of the biggest shift the ad industry has seen since AdWords launched—mobile.”

Of course, it’s not just mobile. The web has evolved to a multimodal, multimedia world, and advertising has followed. It’s mobile, it’s video, and it’s even coordinating your AdWords to drive a shopping campaign that will also play out over several social media platforms.

The last AdWords was built when most of us were still using flip phones.

“Our current product is just showing its age,” Rosenberg says. Indeed, the last AdWords was built before the iPad was released, and when most of us were still using flip phones. Visitors are greeted at their spreadsheet-based campaign page with the list of words they’ve bought–with no way of telling if these words are meant to be working on campaigns together or how each is working across various platforms, unless they dive through all sorts of subpages. And a vague “performance graph” rendered in Google blue piles it all together into one tiny, vague chart.

In turn, Google has met with hundreds of AdWords users around the world to research the new design. Most of its customers are actually small businesses, and upsetting them–much less the Fortune 500s–could put Google’s primary source of income at risk. “It goes far beyond polls or surveys. It’s literally being at a business with our users, watching them use AdWords for hours on end,” Rosenberg says. From there they moved to prototyping and testing in usability labs. “Every tool in our arsenal has been behind this effort.”