TRANSLATION NOTES: Please read some comments at the end of this post.
The blogos’ post explains it better, but in summary it is stated that Google has made a move that probably is the reason that AdSense’s earnings have fallen by almost a half.
Here’s the fourth reason:
4. Google removed half of the offer and sent it to its own coffers.
… Google has assured that it has begun to “make tests run these or not”, in places like Google News, Google Image Search and Youtube. With this the only beneficiary is Google because it is the owner of these spaces.
Then it means that Google possibly may have removed half the AdWords offering and had sent it to these sites leaving us working for nothing (*). Its argument has been that it has done this to benefit advertisers though that benefits more himself.
“Of course, these experiments benefit Google because they generate revenue from new sources – but by ensuring that we show the right ads at the right time to the right people, we’ll add value for users too”
It is as if you have 1,000 advertisers that pay you $100 per month to place their ads on 1000 taxis. Every taxi driver takes at the end of each month $100. So Google decides to remove 500 ads and place them on 500 taxis of its own, this would make that every taxi driver now only has 500 and the experiment lets Google the modest amount of $50,000 additional to what it already earned.
Go there and read it completely.
(*) rascando la pava: This idiom means to work with effort expecting an economic retribution that doesn’t come in the way it is expected.