I've noticed this as well. Full disclosure: At least on my Android device, I noticed that when a commercial ends, if you wait 20 seconds or so and then click "X", the game will reload and you can watch seemingly unlimited commercials. I wanted to raise this because I'll typically watch DomiNations commercials while watching football on Sundays. Most times I try and click the X right away, but you can get caught up with TV, and repeat the process.
It would be good to know if Nexon is going to ban people for watching commercials. As near as I can tell, this is win-win, right? We get a few more crowns per day, they get money(?) for the commercials? When the commercials are for products, or TV shows, or politicians (ughhh, that's happened to me), it seems like those auto-close and go right to the "Processing Rewards" dialog. But when it comes to commercials for games in the Google Play store, it seems like that's where the timeout can lead to watching more commercials.
I wouldn't want Nexon to ban people for watching commercials when they're really not doing any kinda glitch except waiting a few extra seconds to click the X.