SAN FRANCISCO: Facebook users who have hesitated about using the social network's "like" button for certain posts will soon be able to use five new icons that better express their emotions.

Following successful trials in Spain and five other countries, Facebook's 1.5bn users will have the option of using five new emoji images as an alternative to the "like" button, which will still remain as a feature in posts.

Chris Cox, Facebook's chief operating officer, revealed to Bloomberg that the five new icons – Angry, Sad, Wow, Haha and Love – will be launched in the coming weeks. A sixth emoji, "Yay", will not be deployed because the tests revealed it was not universally understood.

Users will be able to access the new "Reactions" images by holding down the "like" button and then scroll through to find the one most appropriate for a post.

While the development is likely to improve the experience for users, it is also expected to be very useful for advertisers who will gain access to more tailored and targeted data.

Associate Professor David Glance, director of the Centre for Software Practice at the University of Western Australia, said the "Like" button can be problematic for advertisers because it does not cover the subtleties of emotions that users wish to convey.

"The degree of reaction is now captured and that's an important feature. It enables advertisers to be incredibly sophisticated about how they post their ads, refining them constantly," he said in comments to the Sydney Morning Herald.

"The buttons, combined with your profile, demographic, your read habits and other information all now goes into the mix," he added.

The news came as Facebook announced that its ad revenue rose 57% in Q4 2015 to $5.6bn with mobile advertising accounting for 80% of total advertising revenue.

Data sourced from Bloomberg, Sydney Morning Herald, Wall Street Journal; additional content by Warc staff