It might also just be a bad period, period. In a matter of a month my click-through and conversion went from very high to mediocre. In fact I suspect that the platform I use might be ripping me off.
Anyway, continue looking at your stats, continue working on the website and if it doesn’t get better in one month then you will know for sure you have a problem. For the website in my signature, conversions are unstable : sometimes it didn’t generate conversions in 2 weeks, other times it converted 6 in a week. It might be the same for you, depending on what you’re promoting.
Edit : if I understand correctly (my spanish isn’t that great), 10k people used your Spin Palace link as opposed to less than 500 for the others.. maybe they just don’t like Spin Palace. Add a poll to your homepage and ask people what their favorite casino is.