The third IPA TouchPoints Survey, involving 6,000 members of the public, noted that 37 per cent of the UK used social media as a tool, while 35 per cent used Facebook.
Belinda Beeftink, associate research director at advertising institute IPA, warned that the facts did not match expectations: 'Social media are there, but as always it is important not to believe the hype.'
She added: 'Obviously social media are growing, but more importantly they are not as big as people think.
'Although popular among the 18-24 demographic, for the broader population they are less prevalent.'
Stephen Waddington, MD of Speed Communications, agreed that there should be a degree of caution when offering social media as a PR tool.
He said: 'We should recognise their role as part of PR, but we must remember they are part of the media mix, as traditional media still remain strong.'
Although only about a third of the population currently uses social media, Beeftink predicted there would be a sharp upward curve as young users grew older. 'If you look at 18- to 24-year-olds, 79 per cent use Facebook for example, up from 39 per cent in 2008. That's a massive growth, so firms will have to be very aware of that.'
Paul Stallard, account director at Berkeley PR, agreed that firms should plan ahead: 'There are more and more people using these resources and they shouldn't be ignored.'