Untill few days ago, I had few ads (in most pages 2, in some 3) from the same type one next to each other. Then I saw that sometimes they aren't shown one next to each other, but one below another, which kind of ruined the whole website look. So I took the ads and wrapped them with a <table> of it's own, where each <TD> holds an ad, so that way they are forced to be one next to each other. After I did this change, I had a drastic decrease in cost per click (from average of 0.25$-0.3$ per click, to somewhere around 0.1$-0.15$ per click). I tried to put it back without the table, and the high cost per click came back along with it. Can anyone tell me what can cause this strange issue? As I want my ads to look nice on my website, but it kills my cost per click. Thank you.
I don't think change your HTML codes will drop your earning, only if you change your contents, Ad placements or the design.
It could be coincidence, but put the code back to how it was before to prove it was the code change that caused the problem.
But, the content wasn't in the table, so how did the bot have a reaction? He did that, and saw it revert.. OP, I think it's just a weird coincidence like andy said.
you have two adsense units next to one another and thats not good... ecpm will drop. Put only one on the very top of your page, another one in your side bar and one below the article see if that changes... kinda hard to test this month since earnings and traffic is down because of the holidays.