Google World Inside view on ads review

This is the first in a series of posts that will provide greater transparency about how we make our ads safer by detecting and removing scam ads. -Ed.

A few weeks ago, we posted here about our efforts in fighting bad ads, and we shared a video with the basics of how we do it. Today I wanted to delve a little deeper and give some insight into the systems we use to help prevent bad ads from showing. Ourads policies are designed with safety and trust in mind—we don’t allow ads formalicious downloads, counterfeit goods, or ads with unclear billing practices, to name a few examples. In order to help prevent these kinds of ads from showing, we use a combination of automated systems and human input to review the billions of ads submitted to Google each year. I’m one of many engineers whose job is to help make sure that Google doesn’t show bad ads to users.

We’ve designed our approach based on a three-pronged strategy, each focused on a different dimension of the problem: ads, sites, and advertiser accounts. These systems are complementary, sharing signals among each other so that we can comprehensively attack bad ads.

For example, in the case of a site that is selling counterfeit goods, this three-pronged approach aims to look for patterns that would flag such a site and help prevent ads from showing. Ad review notices patterns in the ads and keywords selected by the advertiser. Site review analyzes the entire site to determine if it is selling counterfeit goods. Account review aims to determine if a new advertiser is truly new, or is simply a repeat offender trying to abuse Google’s advertising system. Here’s more detail on how we review each of these three components.

Ad Review
An ad is the snippet of information presented to a user, along with a link to a specific webpage, or landing page. The ads review system inspects individual ads and landing pages, and is probably the system most familiar to advertisers. When an advertiser submits an ad, our system immediately performs a preliminary examination. If there’s nothing in the ad that flags a need for further review, we tell the advertiser the ad is “Eligible” and show the ad only on google.com to users who have SafeSearch turned off. If the ad is flagged for further review, in most cases we refer to the ad as “Under Review” and don’t show the ad at all. From there, the ad enters our automated pipeline, where we employ machine learning models, a rules engine and landing page analysis to perform a more extensive examination. If our automated system determines an outcome with a high degree of confidence, we will either approve the ad to run on Google and all of our partners (“Approved”), approve the ad to show for appropriate users in specific locations (“Approved - Limited”) or reject the ad (“Disapproved”). If our automated system isn’t able to determine the outcome, we send the ad to a real person to make a final decision.

Site Review
A site has many different pages, each of which could be pointed to by different ads, often known as a domain. Our site review system identifies policy issues which apply to the whole site. It aggregates sites across all ads from all advertisers and regularly crawls them, building a repository of information that’s constantly improving as new scams and new sites are examined. We store the content of advertised sites and use both machine learning models and a rules engine to analyze the sites. The magic of the site review system is it understands the structure of language on webpages in order to classify the content of sites. Site review will determine whether or not an entire site should be disabled, which would prevent any ads leading to that site showing from any account. When the automated system isn’t able to determine the outcome with a high degree of confidence, we send it to a real person to make a decision. When a site is disabled, we tell the advertiser that it’s in violation of “Site Policy.”

Account Review
An account is one particular advertiser’s collection of ads, plus the advertiser’s selections for targeting and bidding on those ads. An account may have many ads which may point to several different sites, for example. The account review system constantly evaluates individual advertiser accounts to determine if the whole account should be inspected and shut down for policy violations. This system “listens” to a variety of signals, such as ads and keywords submitted by the advertiser, budget changes, the advertiser’s address and phone number, the advertiser’s IP address, disabled sites connected to this account, and disapproved ads. The system constantly re-evaluates all accounts, incorporating new data. For example, if an advertiser logs in from a new IP address, the account is re-evaluated to determine if that new signal suggests we should take a closer look at the content of the advertiser’s account. If the account review system determines that there is something suspect about a particular account with a high degree of confidence, it automatically suspends the account. If the system isn’t sure, it stops the account from showing any ads at all and asks a real person to decide if the account should be suspended.

Even with all these systems and people working to stop bad ads, there still can be times when an ad slips through that we don’t want. There are many malicious players who are very persistent—they seek to abuse Google’s advertising system in order to take advantage of our users. When we shut down a thousand accounts, they create two thousand more using different patterns. It’s a never-ending game of cat and mouse.

We’ve put a great deal of effort and expense into building these systems because Google’s long-term success is based on the trust of people who use our products. I’ve focused my time and energy in this area for many years. I find it inspiring to fight the good fight, to focus on the user, and do everything we can to help prevent bad ads from running. I’ll continue to post here from time to time with additional thoughts and greater information about how we make ads safer by detecting and removing scam ads.

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Making our ads better for everyone

We believe that ads are useful and relevant information that can help you find what you’re looking for online—whether you’re comparing digital cameras or researching new cars. We also want you to be able to use Google and click on any ads that interest you with confidence. Just as we work hard to make Gmail free of spam and the Google Play Store free of malware, we’re committed to enforcing rigorous standards for the ads that appear on Google and on our partner sites. 

Like all other Internet companies, we’re fighting a war against a huge number of bad actors—from websites selling counterfeit goods and fraudulent tickets to underground international operations trying to spread malware and spyware. We must remain vigilant because scammers will always try to find new ways to abuse our systems. Given the number of searches on Google and the number of legitimate businesses who rely on this system to reach users, our work to remove bad ads must be precise and at scale.

We recently made some improvements to help ensure the ads you see comply with our strict policies, so we wanted to give you an overview of both our principles and these new technologies.

Ads that harm users are not allowed on Google
We’ve always approached our ads system with trust and safety in mind. Ourpolicies cover a wide range of issues across the globe in every country in which we do business. For example, our ads policies don’t allow ads for illegal products such ascounterfeit goods or harmful products such as handguns or cigarettes. We also don’t allow ads with misleading claims (“lose weight guaranteed!”), fraudulent work-at-home scams (“get rich quick working from home!”) or unclear billing practices.

How it all works
With billions of ads submitted to Google every year, we use a combination of sophisticated technology and manual review to detect and remove these sorts of ads. We spend millions of dollars building technical architecture and advanced machine learning models to fight this battle. These systems are designed to detect and remove ads for malicious download sites that contain malware or a virus before these ads could appear on Google. Our automated systems also scan and review landing pages—the websites that people are taken to once they click—as well as advertiser accounts. When potentially objectionable ads are flagged by our automated systems, our policy specialists review the ads, sites and accounts in detail and take action.

Improvements to detection systems
Here are some important improvements that we’ve recently made to our systems:

• Improved “query watch” for counterfeit ads: While anyone can report counterfeit ads, we’ve widened our proactive monitoring of sensitive keywords and queries related to counterfeit goods which allows us to catch more counterfeit ads before they ever appear on Google
• New “risk model” to detect violations: Our computer scanning depends on detailed risk models to determine whether a particular ad may violate our policies, and we recently upgraded our engineering system with a new “risk model” that is even more precise in detecting advertisers who violate our policies
• Faster manual review process: Some ads need to be reviewed manually. To increase our response time in preventing ads from policy-violating advertisers, we sped up our internal processes and systems for manual reviews, enabling our specialists to be more precise and fast
• Twenty-four hour response time: We aim to respond within 24 hours upon receiving a reliable complaint about an ad to ensure that we’re reviewing ads in a timely fashion

We also routinely review and update the areas which our policies cover. For example, we recently updated our policy for ads related to short-term loans in order to protect people from misleading claims. For short-term loans, we require advertisers to disclose fine-print details such as overall fees and annual percentage rate, as well as implications for late and non-payment.

Bad ads are declining 
The numbers show we’re having success. In 2011, advertisers submitted billions of ads to Google, and of those, we disabled more than 130 million ads. And our systems continue to improve—in fact, in 2011 we reduced the percentage of bad ads by more than 50% compared with 2010. That means that our methods are working. We’re also catching the vast majority of these scam ads before they ever appear on Google or on any of our partner networks. For example, in 2011, we shut down approximately 150,000 accounts for attempting to advertise counterfeit goods, and more than 95% of these accounts were discovered through our own detection efforts and risk models.

Here’s David Baker, Engineering Director, who can explain more about how we detect and remove scam ads:



What you can do to help
If you’re an advertiser, we encourage you to review our policies that aim to protect users, so you can help keep the web safe. For everyone else, our Good to Know site has lots of advice, including tips for avoiding scams anywhere on the Internet. You can also report ads you believe to be fraudulent or in violation of our policies and, if needed, file a complaint with the appropriate agency as listed in our Web Search Help Center.

Online advertising is the commercial lifeblood of the web, so it’s vital that people can trust the ads on Google and the Internet overall. We’ll keep posting more information here about our efforts, and developments, in this area.

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