The trade organisation's annual AdEx Benchmark research, released yesterday at its Interact conference in Lisbon, showed that over the past decade there has been a €30bn net addition to the online ad market. In 2015 the market grew 13.1% to reach a value of €36.2bn and in doing so it passed the European TV market, valued at €33.3bn.
All 27 markets participating in the study registered positive growth, with 20 markets recording double-digit increases for the second year running.
The fastest-growing markets were Ireland (+29.0%), Bulgaria (+22.3%) and Poland (+21.8%).
The UK was by far the largest single market, valued at €11.8bn in 2015. Internet has been the largest advertising channel by spend in the UK since 2010, according to data from the AA/Warc Expenditure Report, which includes IAB figures.
The UK market was more than twice the size of the next biggest, Germany, on €5.8bn. Then followed France (€4.2bn) and Italy (€2.1bn).
Daniel Knapp, Director of Advertising Research at IHS Technology and author of the research, observed that "over the past ten years, online advertising in Europe has morphed from an afterthought in media buying into an indispensable set of channels for reaching and engaging consumers".
His co-author Eleni Marouli, a Principal Analyst at IHS Technology, added that "online advertising has been the shining star, keeping the European advertising market afloat and again in 2015 lifting it out of decline".
In terms of the three broad segments that define the online advertising market, display advertising outperformed other categories with a growth rate of 17.4% to reach a value of €13.9bn.
Search showed slower growth of 12.6% but it remains the largest online advertising format in terms of revenue at €16.9bn. Classifieds & directories accounted for the remaining €5.4bn.
More specifically, mobile and video continue to be the key growth drivers of the European online ad market, a fact which becomes increasingly apparent, the report said, when looking at the more advanced mobile economies.
In countries like the UK and Ireland, for example, almost half of all online advertising is now generated on mobile.
Mobile display now accounts for €3.5bn or 25.4% of the display market, with a growth rate of 60.5% compared with 2014.
Online video advertising, meanwhile now represents 16.7% of the display market.
Research published in Warc's Global Adspend Outlook, a free summary of future adspend trends that draws from IAB data, finds that mobile adspend will top €82bn worldwide next year. Of this, some €9bn will be for mobile video formats, and a further €25bn for social formats.
Data sourced from IAB Europe; additional content by Warc staff