Social media such as Facecbook and Twitter or blogging sites have become powerful tools that influence what people buy, online researcher Nielsen said yesterday, urging business to embrace the trend.

Nearly three in four people worldwide who use the internet have visited a social networking or blog, spending an average of almost six hours a month on them, The Nielsen Company said in a report.

Of the seven biggest brands online globally, three are social media networking sites - Facebook, Wikipedia and YouTube - it said in its latest report on social media trends in the Asia Pacific region.

"Social media is having a larger and larger influence on purchasing decisions," said Charles Buchwalter, chairman and chief executive officer of Nielsen Online Japan.

"Everyone understands that social media is hot, it's growing quickly and in very unpredictable ways everywhere in the world," he told reporters in an online media briefing.

According to Nielsen's findings, online product reviews are the third most trusted source of information when consumers decide whether to purchase a product, coming after recommendations from friends and family.

From China and India to Australia, online reviews are a major influence in buying electronics items, cosmetics, cars and food, among other things, it said.

An average 32 per cent access social media sites from their workplaces and 31 per cent access them from the confines of their bedrooms.