With the CPM of 150 you could generate up to 3 changeables in a single publication, if you received 20 visits and bought your own publication, now with those 20 visits you can generate only one, I have seen many colleagues who say that to generate a changeable they need 6 or 5 publications I almost always generate it with one or 2, because each colleague who visits me I also visit his last publication in gratitude, so do not be selfish if someone visits you also visit him and you will see that everything will be easier, we cannot be alone in this platform.