US technology website WIRED described Tuesday’s algorithm switch as “likely the biggest change of the past three years.
“And it’s reminder of the wonderfully magnanimous yet deeply selfish way that Google uses its market power to accelerate changes across the rest of the Internet,” it added.
The change comes in the same week as a Google announcement it will launch its own US mobile wireless service, with considerable potential savings for customers using their devices at home and for international travel.
Google argues its algorithm revolution is good for users.
“We want to make sure they can find content that’s not only relevant and timely, but also easy to read and interact with on smaller mobile screens,” Google said in a statement to WIRED.
More than half of Internet searches worldwide are made on mobile phones, a trend that is driven by figures out of developing countries where smartphone penetration is higher than computers.
In 2011, a change to Google’s search algorithm affected 10 percent of English-language websites, while the 2012 change impacted some four percent, according to WIRED.
But the recent change, the extent of whose impact cannot yet be fully measured, has also sent shockwaves among brand owners and marketers, for whom online visibility is hugely important.
“Google has the power of life or death over some websites. A drop in Google ranking can mean a 60 to 80 percent loss in turnover,” e-marketing firm JVWEB’s president Jonathan Vidor told AFP.
Even if mobile phones bring in only a small proportion of revenues, “everyone is scared Google might do something drastic”, Vidor added.