Two period dramas from different network compete head-to-head in viewers' rating. In Korea, SBS "Scarlet Heart Ryeo" trails KBS' "Moonlight Drawn by Clouds"; but internationally, the two dramas compete fiercely to gain audience.
"Scarlet Heart Ryeo" lagged in Korean viewership rating in both Nielsen and TnMS rating system. It only scored average 7.9 percent in Nielsen Korea and 7.8 percent in TnMS. On the other hand, "Moonlight Drawn by Clouds" conveniently achieved 15 percent and 16.5 percent in TnMS and Nielsen Korea, respectively.
However, according to Kpop Herald, "Scarlet Heart Ryeo" ranked the highest in the contents power index (CPI) compared to other drama. CPI is an integrated index developed by CJ E&M and Nielsen Korea to capture wider data than just viewership about influence of contents. The data includes Internet news subscription rankings, direct search rankings, interest, engagements and social media buzz.
On the other hand, stars of "Moonlight in the Clouds" ranked the first and second place on their brand value index, as KBS World Radio reported. Brand value is the measurement of brand power the K-Pop star in term of reputation. The measurement is issued by The Korea Institute of Corporate Reputation that measures different aspect such as participation, communication, media, community, and social indices. Park Bo-Gum scores 12,373,028 the highest, followed by his co-star Kim Yoo-jung with 8,325,552 points.
The two series also compete fiercely in the field of original soundtrack. Soyou from girl group Sistar, Sung Si-Kyung and the queen of ballad Baek Ji-Young lend their voice for the soundtrack of "Moonlight in the Clouds."
Meanwhile artists from SM Entertainment support their fellow agency mate Baekhyun by taking part in the production of "Scarlet Heart Ryeo." Leader of Girl's Generation Taeyeon, fellow EXO member Chen and Xiumin are lining up to sing the original soundtrack.
While other member of Girls Generation Seohyun also plays in the drama, which according to Korean portal Naver, her first appearance in the period drama gained controversy. She plays the last princess of Baekjae Woohee.
Both "Scarlet Heart Ryeo" and "Moonlight Drawn by Clouds" drama airs at the same hour at 10 p.m. KST on SBS and KBS, respectively.