Yesterday when Blogger.com, one of the top free blogging service provider owened by Google, made some updates to their system it resulted in a temporary broken connection between Google Adsnese and Blogger. As a result of this glitch, almost all the blogs that were hosted on Blogger.com and have Adsense ads on them started showing only PSA(Public Service ADS) which unfortunately generates revenue neither for Google nor for Adsense publishers.
Immediately after this issue was spotted by publishers, they reported this in various forums and groups, including Official Adsense group, so that Adsense team could take immediate action and restore the ad serving to all Blogger blogs. And they did what was required. They fixed this problem and have now started serving Adsense ads back on all Blogger hosted blogs.
I just feel sorry for some bloggers who had lost some serious amount of revenue and were severly effected by this temperoray glicth.