SYDNEY: The growth of online advertising expenditure in Australia will slow this year, but the medium is still set to register a double-digit improvement in 2009 on an annual basis, GroupM Interaction predicts.

According to the company's estimates, digital adspend – including internet display and search ads, as well as mobile – will rise by 14% this year, to around A$2 billion ($1.7bn; €1.2bn; £1.1bn), compared with the uplift of 27.6% recorded in 2008.

Within this, the total outlay on online search will increase by 20%, to A$968 million, down from the expansion rate of 29.7% last year.

Display revenues, including online classifieds, will reach A$985m, up 9% year-on-year, before climbing to a total of A$1.1bn in 2010.

Mobile budgets will also be 25% higher in 2009, taking this channel to a value of just A$10m, with a further upswing of 30% in 2010 as consumers and advertisers increasingly take to the medium.

While social media is expected to be another key growth area, GroupM argues its influence may not translate into improved adspend, as brands continue to adopt more informal methods of connecting with consumers using this channel.

Data sourced from B&T; additional content by WARC staff