This is one of the most common mistakes among new adsense users, especially those who think that they are going to make money right away, but nobody goes to their sites. They think that no one will be able to track their clicks on their own ads. That is absolutely wrong. Google tracks your ip address, along with a lot of other things like location, and can easily tell when you are clicking on your own ads. People try to go on other computers and click on their own ads, but that doesn’t work either, because often they log in to their adsense account after to see their revenues increase. Google knows. You may think that they don’t, but they do. And ultimately you are costing yourself in the future. If no one catches you, those advertisers may not have made enough profit off of the traffic generated from their ads, and they will think that the program is not worth their time or money, and you could not earn from their ads ever again. So, don’t click on your own ads, it costs everyone.