LONDON: Television advertising is the single most important factor in driving people's conversations about brands, a study has found.

Data2Decisions, the marketing effectiveness consultancy, and Thinkbox, the TV trade body, analysed over 500,000 data points for 36 brands across three categories: retail, finance and drink.

Among the main findings, exclusively revealed at Warc's recent Measuring Advertising Performance event, were that paid-for advertising accounts for 72% of incremental brand conversations, while TV spots alone drive 51% of word of mouth (WOM).

And there is a carry over effect: the research showed TV advertising drives word of mouth for a number of weeks after initial activity. The impact can last for some months so that running TV advertising every three-to-six months will help maintain WOM levels.

"Paid advertising's causal effect is often overlooked with too much emphasis put on what is easily counted or highly visible," said Neil Mortensen, Research and Planning Director, Thinkbox.

"This research," he went on, "has revealed for the first time what actually stimulates people's brand conversations and it is clear that investment in advertising – and especially TV – is key to getting people to talk about your brand positively."

Katherine Munford, Director at Data2Decisions, added: "Owned and earned online platforms amplify the effects of paid media by providing hubs for conversation, but delivering a long-term impact is best achieved via paid media – with the audio-visual power of TV being especially powerful."

After TV, other factors tail off rapidly. PR, events and brand news account for 19% of word of mouth, with online search display and affiliate advertising 12%, and changes to brand products or services 9%.

Print advertising contributes an additional 4%, ahead of outdoor advertising on 2%, direct mail on 1.5%, cinema on 1% and radio on just 0.5%.

And despite the widespread marketing focus on social media, some 90% of brand conversations take place offline, either in person or on the phone.

Data sourced from Thinkbox, additional content by Warc staff