hello since beginning of this month CTR from a site seem too high ( normally only 4% , but now around 7-8% ) I want to contact google adsense support, but cannot find form to submit report ( in the past I think I can do this, but not for now ) anyone can help ??
That really isn't that much or worth contacting google. Not to mention it is nearly impossible to do so for something so simple. They would most likely never see your email, if they did they would just delete it. Heck I have seen others talk about 50-100% range for a given day so 7-8% is not much to worry about.
No need to contact them, this ctr is not too high at all. This could be simply because a new advertizer started this month to display an ad that is very relevant to your topic, so users click it.
You may use: http://www.google.com/support/adsen...n_EN&contact_type=invalid_clicks_contact&rd=1 If you think you have experienced invalid clicks or an huge increase in traffic. They will almost never reply though.
It is OK even if you get a good CTR of 20-25%. Google will always monitor you. So no need to worry about it.