Three days ago, I've changed my ads and changed colors, respectively: Border #ffffff, Title #0000cc, background #ffffff, Text #000000, URL #0080000. My CTR went up from about 1% to 6%. I'm not worried, but i want to know if there is a maximum permissible values for CTR.
No, there is absolutely no maximum ctr. As long as you are following the TOS, you having nothing to worry about. While it depends on the niche, 6% is not considered very high.
I don't think so if you think you are facing any hike without any good news than contact google team but after 20% ctr they start tracking stats in serious moods .
Wow, this is good to know. I thought they didn't worry about CTR at all, unless there were I guess obvious signs of fraud.
Well, CTR is click through rate. I have seen people getting even up to 10% CTR as normal but when the level reaches dangerous proportions, suspect for click fraud and report the matter to google at once