Still, the bad actors are more determined than ever to game the system

May 26, 2012 11:41 GMT  ·  By

Google is the biggest search engine in the world and also has the largest ad network. As you can imagine, there are plenty of people trying to game and abuse both. But, whereas Google can't be responsible for the sites found in search, it is responsible for the ads it serves, even though those ads were created by third-parties as well.

Ads are Google's bread and butter so it's very important that its ads are trusted, one bad ad can ruin years of building trust.

But, with billions of ads submitted in a year, making sure the bad ones stay out is hard. Still, Google says it's doing better than ever before.

Last year, it disapproved 134 million, as many as in the previous three years combined. Only 56.7 million ads were disapproved in 2010, 42.5 million in 2009 and 25.3 million 2008.

Ads that get rejected are usually for policy violations. Many of those ads are honest mistakes and the advertisers pushing them fix the problems and move on.

Of course, there are those that strive to push malicious ads, from spam to malware, and they're getting better all the time, just as Google implements new measures all the time.

For example, Google suspended 824,000 accounts in 2011, again a record number. Only 248,000 were suspended in the previous year, 68,500 in the year before that and just 18,100 in 2008.

"We find that there are relatively few malicious players, who make multiple attempts to bypass our defenses to defraud users. As we get better and faster at catching these advertisers, they redouble their efforts and create more accounts at an even faster rate," Google wrote. "Even in this ever-escalating arms race, our efforts are working."

Google conducts surveys to gauge the quality of the ads it pushes. It says that the percentage of people who complain about a bad ad has halved in 2011 compared to the year before. Of course, that's not to say that there are fewer bad ads, just that they are fewer compared to the total number of ads served.