ENABLE BOTH IMAGE AND TEXT ADS TYPES TO GET HIGH CPC RATES
GENERALLY, THERE ARE FIVE TYPES OF ADSENSE ADS VIZ. TEXT, IMAGE, ANIMATED IMAGE, RICH MEDIA AND FLASH. ALL THOSE AD TYPES ARE CATEGORIZED INTO TWO TYPES ONE IS TEXT ADS AND ANOTHER IS DISPLAY ADS.
I STRONGLY, RECOMMEND ALL OF YOU TO ENABLE BOTH TEXT & DISPLAY ADS TYPES FOR YOUR ALL ADSENSE AD UNITS. IT WILL INCREASE THE NUMBER OF ADVERTISERS TO YOUR SITE ENSUING HIGHER CPC RATES FOR THEM.