A campaing Adsense only is profitable if its done on pages that have rich content and its interestingsting for the surfer. A siple copy-paste of another webpage dont work.
The technology of the search engines detects when the content is overexposed on internet or if is duplicated and this will get our pages penalized on the bottom of the index of the search engine or banned. This penalization affects our way of get traffic to our website and without traffic our page is useless.
If our content is original this will make the people gain nterest on it, and if we choose the correct keywords, our ads of Adsense will be more atractive to the readers of our site. In fact, this is a critical factor, cause to get the user make clicks on the ads is necessary those ads grab his attention, and the best way to make this happen is showing ads related to what the user is reading or looking. If our content is related to cars, is absurd showing ads of lencery. Nobody will click on that.
Its necessary choose the right disposition of the ads also. Adsense offers several formats to help us to fit the ads in the page. Would be good not to emphasize them, but not make them...