Google has begun rolling out its mobile-friendly algorithm update, which will prioritize mobile-optimized websites in its search rankings.

The search giant announced in February that it would add mobile usability as a ranking signal starting April 21. The algorithm will not change the ranking of searches performed on desktop computers.

But so far, the change — which was being referred to as “mobilegeddon” in recent weeks — has had only a very modest impact. As of April 22, industry experts were seeing only a 1.7% difference between desktop and mobile domain rankings.

It may take around a week for webmasters to start seeing substantive differences, Google cautioned in an April 21 blog post.

The Google Webmaster Central blog also reminded webmasters that while they should strive to make all pages on all their websites mobile-friendly, and that doing so at any point in time would help them to regain positions lost in the update, this ranking signal isn’t so strong that it will override all other important factors. “The intent of the search query is still a very strong signal — so even if a page with high quality content is not mobile-friendly, it could still rank high if it has great content for the query,” the post read.

Google has maintained from the start that the algorithm update is simply a response to the fact that consumers heavily prefer mobile-friendly sites. According to the most recent data, 74% of users say they’re more likely to return to a site that caters to mobile visitors.

Google often adds what it perceives as consumer demands as ranking signals as a way of encouraging (some might say enforcing) more user-friendly web behaviors on the part of businesses.

“I am still amazed at how ranking factors can cause such a frenzy from website owners,” said Andreas Huttenrauch, Chief Digital Strategist for Globi Web Solutions. “The key to having a successful website has not changed — and probably never will. Give people what they want: high quality relevant content.”

And regardless of the eventual impact of the update, it does appear that Google has been successful in incentivizing a transition to mobile or responsive sites; according to Google’s own data, there’s been a 4.7% increase in mobile-friendly sites in the past two months alone.

“Why would it suddenly be important to have a mobile site just because Google is using this as a ranking factor?” questions Huttenrauch. “Obviously mobile users were not important to those website owners before the update. Putting ranking factors ahead of usability factors is putting the cart before the horse.”