Thailand has introduced the dual-screen system to measure TV ratings on both TV and online media, the first country in Asia-Pacific to do so.
This new measurement is done with a collaboration among ratings agencies, advertisers and the media network.
GroupM's Mindshare, Dutch conglomerate Unilever and Nielsen Thailand have jointly debuted the dual-screen measurement, which will evaluate TV ratings on TV and online media in parallel.
The measurement aims to track changing media consumption among Thai people, particularly young adults in Bangkok and urban upcountry, who view TV content via both TV screen and smartphones and other online channels.
Piyanuch Meemook, head of digital strategy at Mindshare, said the ad industry was facing a decline of viewers, resulting in less investment in efficient advertising.
This is caused by an increasing number of TV channels, the fragmentation of viewers and the growing trend of multi-screen habits.
"Time spent on personal computer, smartphone and tablet totals 358 minutes a day, outpacing 78 minutes on TV," said Ms Piyanuch.
Online usage is the highest and maintained throughout the day, while TV viewing obtains a high rate during prime time.
According to a survey conducted in Bangkok and urban upcountry by Nielsen, the number of dual-screen viewers is predicted to rise to 49% by 2020 from 40% in 2015.
While the number of TV-only viewers may decline from 59.5% at the moment to 49.75% in the next five years, internet-only viewership may grow moderately from 0.5% now to 0.75% in 2020.
Youngsters and working adults are light TV viewers.
Trends in media consumption in Thailand resemble those of Singapore, Hong Kong, Malaysia and New Zealand.
Ms Piyanuch said findings from the survey came from nearly 100 campaigns by Unilever Thailand during 2014-15. The sample size was 66,000 respondents, of which 6,700 were cross-screen viewers.
The survey found that TV is still a dominant media among Thais but the viewer number has a negative trend, while multi-screen behaviour is growing significantly as online media could be called "mass media" for youngsters.
Online is more cost-effective in reaching a specific target group. Therefore, using a mix of TV and online can deliver a higher reach than using TV alone.
Mobile is the key engine to gain further reach, which means that more budget allocation on online media will benefit advertisers, Ms Piyanuch said.
The US was the first country to begin dual-screen measurement, while Thailand is the first in Asia-Pacific.