Is clicking on advertisements of companies that I dislike a good strategy to cause them to waste money?

You actually can’t harm them this way. By clicking on the same ads on the same site. Google will actually pinpoint your IP, location and MAC address. That way you will only harm yourself not them. Bad tactic. After a series of few clicks, they will not consider any input from the same IP address. They will throw you in the blacklist. Google has an advanced CPC, CPM and CPA formula. When they will find it out that there are so many clicks and no action or conversion on the ads they will find out that they are being cheated. The only way to earn money through your own ad clicks is to open up your own website or blog a few times a day click on ads yourself only once. The important thing is the ads arrangement and sequential position. Your ad's placement should be between the blog posts in such a way that the user thinks that it is a part of the post. In that way, you can earn a lot of money easily by less traffic on your site. Ads positioning and placements play a vital role. Secondly, the ads should be relevant to your blog’s or website’s Niche. Have a look at this page for getting an idea of better ads placement and positioning. Charming Treasures Online Gift Store