We don't display ad within (inside) educational content (notes) as it will be difficult for people to read the notes. Such pages will also see only minimal ads. This will allow people to read notes with concentration.
Contents such as downloads and resource links may have ads in both sides, as this will be used by users usually only once and does not require any concentration to do so. Example: http://javajee.com/downloads-sample-questions-for-oca-java-se-7-programm...
Why we place ads?
We are providing the contents for free. However we will also have expenses for domain renewals, hosting renewals and even for conducting the Helping Hand Program. Ads are a way that can attract that income without you needing to pay. However, we will not be placing them within the educational contents and distract you, even if that means a loss of revenue.