I'm actually not an expert or anything, but I can only say this based on observations with James's previous pairings. Jiranee had a LOT of advertisements/magazines, the whole shebang, after Puttipat because it generated hype even after it was shown (in the SJ series, it was Ratchanon with Taew x Bomb that had the biggest ratings but Puttipat generated a lot of hype.) If I'm not mistaken, this is what the people call "krasae" or something (i'm sure I misspelled that so don't quote me on that. haha). So since it was the one that people frequently tweeted about and posted about and fangirled about, even if its ratings had not been as high as Ratchanon, basically, the Jiranee ship was launched. Padiwarada's ratings started at the 4-5 levels too but eventually went up to almost 9. And then it was also exported to Cambodia, etc. so it was quite hyped. James and Bella had a ton of magazines together.
Ruk Sud Rit with James and Punch actually generated higher ratings compared to Padiwarada with Jiranee but you don't see James and Punch anywhere together, do you? Well, to be fair, Punch is more of a singer and I think more active in other channels so there wasn't really much promotion about them after. So I suppose that's an example of high ratings, low "krasae". Buang Hong with James and Kim, surprisingly, have higher ratings than Game Sanaeha, but you don't see these two together in promotions either.
So all is not lost if the ratings are low. As long as they generate hype and continue to trend in Thailand, they might get commercials too. Right now, at least James and Taew are both in AIS so that's an opportunity for them. Hopefully other products like Shiseido and food products get them as well. But then you guys have to remember this koojin thing is a double edged sword. JT is effective in weaning out James from Bella, and to some extent, Taew from Mario (not that they were tied together in the first place) but would you really like to see these two together over and over again? (I think the answer is yes.
) At the very least, we all know the good rapport between these two and surely, even after GS, they'll remain good friends, and who knows? James might just sing in Taew's wedding.