Search Engine Watch columnist Christian Arno pointed out that different companies are ahead of Google in several important international markets.
Users of professional SEO services were advised that this includes Baidu in China, Yandex in Russia and Yahoo! in Japan.
Mr Arno said this presents considerably challenges because of their different rules – for example, Baidu doesn’t take into account link building in its rankings, while Yandex penalises websites which contain pop-up ads.
“Developing SEO specific to each country’s dominant search engine is just as important as creating language and culture-specific websites in the first place,” he added.
Earlier this week, a report by Wedbush Securities forecast that Facebook will offer a growing challenge to Google as the social networking site develops its search operations, reported the Barron’s website.