Majority of the income for bloggers come from displaying the Google Adsense Ads on the blog posts. When visitors click the ads, Google pays money to the bloggers.
In few cases Google displays public service ads instead of the regular ads. When public service ads are displayed, bloggers does not get paid for clicks made on the public service ads. This really hurts the income of bloggers.
Here is a Google Public Service Ad displayed on one of my friend’s blog
Lets look at the common reason why Google displays the public service ads. Public service ads are displayed
- when porn movies, picture or any other sensitive information is posted in the page
- if your created a new Adsense account and the account is not yet approved
- when the web page does not contain enough content
- when the ad unit is set to Image Ads only
- when you forget to verify the PIN number. Google issues PIN number through postal mail to new Adsense accounts to authenticate their address and other details. The Adsense account holders must enter the PIN number in Adsense settings page.
If public service ads are displayed on your blog, then try to identify the problem by understanding the common reasons and fix the problem. For information you can read this Google Adsense Help page