Intrusive ad formats and unskippable pre-roll motivate people to use ad blockers most, according to a survey.

findings from an online survey for tech specialist Teads across markets in the USA, UK, three South American and four European countries found that giving users choice to view an ad reduces motivation to block them. Some 84 per cent of respondents said they would

reconsider the installation of ad blockers if the ad experience provided them with choice.

More than half (52 per cent) ranked pre-roll as the most intrusive video format.

All but two per cent would reconsider using blockers if ads were more relevant or they could avoid them, or the associated sound.

Some ads were welcome: even the idea of ads that generated revenue for "publishers I like" won approval with 14 per cent of respondents. Non-intrusive, entertaining and informative ads were least likely to prompt blocking.

The company urges publishers to:

-integrate advertising formats which create a seamless user experience;

-leverage features that give users control of the ad experience through choice

-limit the use of advertising formats that are considered intrusive such as pre-roll

-create formats which are built specifically for mobile to improve users' perception of mobile advertising; and

-strategically use targeting to ensure ads are relevant to the user.