Ninety-seven percent of Google’s revenue comes from advertising – that’s a staggering figure when you consider the company netted $23.7 billion last year.

So when it comes to tweaking the design on the homepage that has made Google the number-one search engine for 268 million users a day, the company is proceeding with extreme caution to avoid tampering with the success of those paid advertisements.

Though Google’s home page and the following results pages that appear after the user has typed in a query have gone through several subtle redesigns over the years, this new project is much more extreme, and therefore much more volatile. If it’s successful, it will improve the user experience so that Google can continue to maintain its edge over new search offerings like Bing and Yahoo!.

Critics say Google risks losing the feature that gives it their number-one appeal in the first place, a streamlined home page with no bells and whistles that makes the search experience easy. On the flip side, Google’s algorithm may be outdated, as Bing offers real-time results in tandem with algorithms that help determine relevance.

Google is gambling on the idea that a redesign will improve the user experience, and therefore the ad revenue as well. Whether the gamble will pay out is up to the enormous team of designers it already has likely working day and night on the task.