Now if you think that is impressive wait till you hear how much the ad cost. According to Allkpop, the ad would cost about USD 2.5 million if it was up for a month. That would be about KRW 3 billion. Since the ad was up from the 7th to the 15th, then it is speculated that the fans spent a whopping KRW 700 million or USD 600,000 on the ad.
It's amazing how a K-Pop idol can receive so much love and support that fans would be willing enough to spend a lot of cash just to make their idols feel special. With such an amazing gift, there is no doubt that Chanyeol noticed it.