Up Close With Google's Contextual Ads

As explained in the Google Throws Hat Into The Contextual Advertising Ring article, Google is now delivering contextual ads into web pages. This article looks more closely at how the system operates.

Where Do The Ads Come From?

At the moment, anyone in the AdWords program is having their paid listings also distributed through Google's new contextual ad network, if they target the English language and the US, the UK, Australia, Canada or all countries.

Where Do The Ads Appear?

The sites in that network, at least those publicly announced, include:

  • Howstuffworks.com

  • Blogger.com

  • Weather Underground

  • Google Groups

  • The Google Directory

I Don't Want To Be In The Program!

"But I didn't want my ads in this network," you say? Don't worry. Google has not charged you for any clicks that have come from contextually placed links, yet. This will continue until March 12. On that day, you will begin being charged unless you choose to opt-out of the program.

To out-opt, adjust your distribution preferences as explained in the FAQ page about Google's contextual program.

How Are Ads Delivered?

Advertisers in the program insert special code into their pages, typically in place of where they might run more traditional ads, such as banners. The code makes a call to Google when a user views the page, which in turn causes Google to insert ads that are targeted to the page.

"We can look at any page on the web and decide what are the best ads we can target," said Google's Susan Wojcicki, director of product management for Google's ad syndication programs.

In particular, Google already has a good idea of what many pages on the web are about. Because of that, for a particular page, it summarizes key terms and uses these to pull back ads targeting those terms.

"We use an analysis very similar to what we do for search," Wojcicki said. "We look at font size, the words on the page, interesting things like the link structure of the web."

In some cases, Google may come across a page it hasn't yet seen before. In that case, it will serve out an ad with links to charity web sites. It will then index the page, so that in the future, it can target it with paid listings.

Can I Target A Particular Page?

Google is not "tagging" pages as being about particular terms. For example, take a page with content about auto transmissions. Google hasn't labeled this page explicitly to receive ads in the AdWords program that are targeted to those words.

Instead, Google extracts the terms it believes a page is about. For our example page, if it makes a lot of references to "auto transmissions," then those words would be among those Google would likely target. However, it could also add the word "car" to the mix, as well, realizing the the words "car" and "auto" are closely related.

In another example, Wojcicki said that a test page about Gennifer Flowers, a woman President Bill Clinton had an affair with, didn't bring up ads about buying flowers but instead about legal advice. It's a case where Google is depending more on links rather than the page's actual content to better understand what it's related to.

In short, you can't force your ad to appear on a particular page, because there's no way for you to know what terms Google itself is determining to be relevant to that page. However, with some good guessing, you'll improve the odds that this will happen naturally.

"The advertiser won't be able to say, 'I want to be on a specific page.' But if they have words that are very targeted to that page, then they should show up on that page," Wojcicki said.

What If Google Guesses Wrong?

As you can see, Google's working some behind-the-scenes magic to understand what a page is about. The company admits that advertisers may have doubts.

"We need the advertiser to trust us that we are doing the right thing, and I think that's hard for some of them," Wojcicki said.

To build that trust, Google reassures that it has done testing that has found that the contextual ads seem to convert at the same rate as its regular ads. This testing was done by Google having worked with two third-party search engine marketing firms. These firms placed some of their largest clients into the contextual program, then compared the conversion rate of contextual clicks to those from the search clicks.

Still not convinced? Then Google encourages you to make use of new reporting that shows explicitly the clicks coming from contextual ads, to see if they are bringing your conversion up or down.

Ultimately, you also have the option not to take part in the program, of course.

"They can opt out if they aren't happy with it, but we think they'll be happy," Wojcicki said.

Can I Carry The Ads?

All set to become a Google affiliate and start earning money for ads, in the way that sites have long done with Amazon? Don't get your hopes up, at least for the near future. That's because Google isn't following a model where anyone can join easily, just by filling out an online form

Instead, Google uses its own media buyers to get unused ad inventory from these sites at CPM (cost per impression) rates. These sites get paid by Google, while Google in turn hopes to earn more than it pays off the clicks generated by its own contextual ads.

"This is a huge benefit anywhere there's a run of site inventory," Wojcicki said. "It is a way to ensure it's targeted, even if it is run of site. It's a great opportunity for them to sell all their excess and remnant inventory."

Unfortunately, establishing the ad contracts means that Google cannot easily process all the sites that would like to be involved.

"Right now, the biggest bottleneck is that we are limited by the number of media buyers we have," Wojcicki said.

Certainly you can apply to be considered. But expect that Google is likely to deal with large content sites with lots of ad inventory first. Perhaps someday, you might see some easier access for smaller web sites.

We don' t have the infrastructure right now to support all the small sites, so I wouldn't want to create all types of excitement over it," Wojcicki said. "That's something we can consider down the road, opening it up to a wider audience. Right now, what it is open to is anyone who has a lot of page views that are unsold."