'Alternate Ads' in "Google Adsense"

What are 'Alternate Ads?'

Alternate ads allow you to utilize your ad space in the event that Google is unable to serve targeted ads to your page. By default Google serves PSA's (Public Service Ads) which are free ads and you would not receive revenue from them,although their impressions and clicks are counted by Google.

There are three options available in the account which are :

• Show PSA (public service ads)
• Fill background with solid Colour
• Show ads from another URl which are also known as 'Alternate Ads'.Alternate ads, if specified, will be shown when there are no targeted ads available for your page. The ad space will not be branded as 'Ads by Google'.Those ads can be from another advertising company also and Google does not keep an account of those ads.