How Google, Yahoo Content Ad Matching Really Works

This week we’re taking a detailed look at how content advertising campaigns really work — how Google and Yahoo match your ad groups to appropriate pages of site content, and display your ads there.

Here’s how Google’s AdWords help files describe the process:

“Google continually scans the millions of pages from the content network to look for relevant matches with your keywords and other campaign data. When we find a match, your ad becomes eligible to run on that page. Google’s extensive Web search and linguistic processing technology can decipher the meaning of virtually any content network page to ensure we’re showing the most relevant ads.”

Yahoo’s explanation is similar.

The algorithms seem straightforward and elegant: software examines words on a content network site page and examines words in your campaign’s keyword list, and displays ads when those words (and their meanings) match.

The last sentence of Google’s explanation is, unfortunately, an exaggeration. Google and Yahoo’s content-matching algorithms are inefficient — they don’t do a good job of accurately matching a content campaign’s ad groups to appropriate site pages. So, ads appear on pages and sites that are completely unrelated to the advertiser’s products or services. And as explained last week, this little-understood fact is the main reason content campaigns fail to perform as well as search campaigns.

How Matching Algorithms Actually Work

Content network site pages are analyzed, and the search engine’s algorithms decide to assign a “theme” or category to the page. The category is chosen by the software from a finite list.

For Google AdWords, this is a list of 594 themes — the same ones offered to advertisers when they are choosing sites for a placement targeted content campaign (formerly called site targeted campaigns). Yahoo’s list is similar — and we’re working on obtaining that list for readers.

The keywords and ad text of the content campaign are similarly analyzed, and each ad group is assigned a category from the same list. The matching algorithm tries to establish a logical “sub-category” that helps the algorithm decide which subsets of all themed pages are most relevant.

The algorithms also act on negative keywords (a special keyword match type that weeds out irrelevant searches) that are included in the content ad group. Consequently ads will not appear on site pages that may match the selected theme, but contain the ad group’s negative keywords.

Your ads are displayed on pages selected through this process.

With this in mind, let’s revisit the “Five Commandments” of content advertising.

1. Run your content campaigns separately from your search campaigns.
2. Separate content campaigns into small ad groups — each with, ideally, 20 to 40 keywords — and never more than 50.
3. Don’t bother using different match types — e.g. phrase and exact match in Google. Match type is ignored by the content matching algorithms.
4. Don’t bother with separate bid prices for each keyword — these too are ignored, and the search engines operate based on the ad group’s default bid. Use negative keywords to help the algorithms “figure out” sub-categories of content network site pages where your ads should not appear.
5. Create ads and keyword lists that, taken together, will match a particular theme or category.

Next week: a few examples of well-constructed ad groups. With that under your belt, it’ll finally be time to turn those content campaigns back on!

Join us for SES Chicago from December 3-6 and training classes on December 7.