LONDON: Social networking websites may be gaining ever-increasing numbers of users around the world, but they are unlikely be able to match their popularity with similar levels of adspend, according to WARC Online's new columnist, Tummler.

eMarketer estimates social networking websites' ad revenues will reach $1.6 billion (€1.3bn; £1.1bn) in the US by 2013, but Tummler points to the reservations of figures from Rupert Murdoch to Facebook ceo Mark Zuckerberg as to whether these services can effectively be monetised.

WARC Online subscribers can view Tummler's first fortnightly column in full by clicking here.

Data sourced from WARC Online