Google has a program for website owners (publishers) to carry Google advertisements on their websites. It's called Google Adsense. And some things happened during the month of May which have many website owners (publishers) questioning Google and even being upset with Google.

These are the two basic complaints:

1. At the end of May, Google told the publishers that their actual advertising revenue for carrying Google ads was far less than what their daily "revenue reports" showed. In some cases, publishers said their actual revenue was as much as 90% below their "estimated revenue."

2. During May, the price paid to each publisher for the ad, the so-called "cost per click" dropped and in some cases the drop in revenue per ad dropped dramatically.

There are explanations for these events that publishers (website owners) might not be happy about.

In the case of "actual revenue" being lower than "estimated revenue" this could be because of invalid clicks -- where "bots" click on ads. Google has ways of determining that certain "clicks" on ads may have been accidental or were by "bots" checking links. If a click is "too short" it can indicate a bot or an accident.

In the case of cost per click (CPC) dropping it could be a sign that business is getting tough for Google and advertising activity has dropped, or it could be a sign that the Internet is now so overloaded with websites with advertising opportunities that competition among websites has lowered prices for ad space.

Also, Google might have seen a drop in the number of advertisers competing for ad placement and as a result it had to lower prices.

As more websites are created with more of them using Google Adsense, ad costs will drop because there are more websites wanting the ads.

It's supply and demand. As there are more websites with ad space, prices for each ad will drop.