I noticed that if an user click for example 2 times on my ads, it get paid just 1 time. Is a good idea than try to find a way to make ads clicable 1 time only?
they will remove that clicks using the same adcode (unique encrypted adcode) so that advertiser wont get charged twice for same clicks
Google is smart enough to track the ip address of the visitor who click the ads. So it's possible that they count those clicks as one to protect also their advertisers.
Let me say there is no rule of thumb like you wont get paid if user clicks two times. Google is smart enough to differentiate from valid clicks and non-valid clicks. Unless it is non-valid click, you will get paid for every click you are getting.
Yes if visitor clicks on your ad rapidly more than once it will be counted as single click instead 2 or 3, because when visitor clicks on your ad his/her ip address get noticed so if clicks comes from same IP rapidly it will be counted as single click.