Now that you've identified your inventory, it's time to design your ad unit hierarchy and the custom criteria that you'll be using as a prerequisite to building your inventory.
Your inventory is made up of two major components: an ad unit hierarchy that describes the relationship between individual ad units, and a list of custom criteria that is used to further distinguish the ad slots on your website. This article walks you through how to determine your targeting requirements, how to choose between ad units and custom criteria, and how to build out your ad unit hierarchy.
1. Determine your requirements
To determine your requirements, we recommend that you start by identifying the ways that you want to sell, report on, and forecast your inventory. As a best practice, you should include representatives from Sales, Ad Ops, Web Development, and your reporting stakeholders in this discussion.
You may find it helpful to review your sitemap, ad specs, rate card, sample reports, and any existing campaigns / IOs for this information. Think carefully about the targeting options that you offer your advertisers today as well as the targeting options you'd like to offer them in the future. The more specific you can be about your requirements the better. You can use a bulleted list to quickly and easily document your requirements.
Example: List of requirements for a traditional newspaper website
Imagine your site is structured like a traditional newspaper with sections for sports, finance, and weather. Your requirements list might look something like this:
- Target a line item to a specific section of your website.
- Target a line item to all of your sports subsections.
- Exclude your finance section from Run of Network (RON) line items.
- Target all of your sports, finance, and weather landing pages.
- Target a line item to a specific gender anywhere on your website.
- Target a line item to a specific sports team anywhere on your website.
- Target a line item to your visitors that are based in Canada.
Now that you've determined your requirements, it's time to use them to help you choose between ad units and custom criteria.
2. Choose ad units and custom criteria
In general, our most successful clients maintain a simple, structured ad unit hierarchy with a few custom criteria. We recommend building a network that's easy for advertisers to understand.
For each of the targeting requirements that you've identified in Step 1 above, compare the following ad unit and custom criteria features to determine what you should use (for bandwidth, geography, or operating system, you would generally use system-defined criteria):
|Ad unit features||Custom criteria features|
Ad tags, which represent ad slots on your website, are made up of a single ad unit, but can contain multiple custom criteria.
Ad units are primarily used for targeting sections of your website or content that have a hierarchical relationship. By targeting a parent ad unit, you automatically target all of its children as well. This is commonly known as "flow-down" or "vertical" targeting.
Custom criteria are primarily used to target characteristics that are common across your website. This is commonly known as "cross-site" or "horizontal" targeting. There are two types of custom criteria: user-defined and system-defined:
Example: Chosing ad units and custom criteria for a traditional newspaper website
Continuing our example of a newspaper website, the table below illustrates how you would use ad units, key-values, and system-defined criteria to meet those requirements.
|What you want to do||What you should use|
|Target an ad to specific section of your website.||Ad units are primarily used to target sections of your website.|
|Easily target an ad to all of your sports subsections.||Ad units provide "flow-down" targeting which enables this.|
|Exclude your finance section from Run of Network ads.||You should mark the finance section as a special ad unit.|
|Easily target all of your sports, finance, and weather landing pages.||You should combine all of your landing pages in a placement.|
|Target an ad to a specific gender anywhere on your website.||Key-values provide "cross-site" or "horizontal" targeting that enables this (e.g.
|Target an ad to a specific sports team anywhere on your website.|| Key-values provide "cross-site" or "horizontal" targeting that enables this (e.g.
|Target an ad to your visitors that are based in Canada.||Geography is a system-defined criterion, which is handled for you behind the scenes.|
Now that you've decided how you'll be using ad units, key-values defined by you, and system-defined criteria to design and target your inventory, it's time to build out your ad unit hierarchy.
3. Build out your ad unit hierarchy
Identify the structure of your network
We recommend reviewing the navigation of your site, the variables in your CMS, and your URL structure. Some publishers find that creating ad units based on publicly viewable information like website navigation or URL structure makes it easier for advertisers to understand where their ads are appearing.
Identify the parent/child relationships between the different sections of your website
The topmost sections of your website should also be the top-level ad units in your network. If you manage multiple websites or companies, you can use the top-level ad units to represent each of those websites and companies. Subsections should be second-level ad units, subsections of subsections can be third-level ad units and so on.
Example 1: Traditional newspaper website
Example 2: Multiple websites / ad network
Keep it simple
Your inventory structure can contain up to five levels of hierarchy if you are using Google for Publisher Tags. However, you aren't required to use five levels, and we recommend only creating lower-level ad units for sections that generate a significant amount of traffic. We find that ad units that generate at least hundreds of daily impressions are the most useful for targeting, forecasting, and reporting.
You should only create a unique ad unit for unique URLs that you target frequently and that get a significant amount of traffic. For example, you may want create a unique ad unit for your home page and for top read articles, but we don't recommend creating a unique ad unit for every article. Our most successful clients typically have fewer than 50 ad units at the highest level of their hierarchy and within each branch.
We recommend using all lowercase letters and avoiding special characters when creating ad units. You can only use alphanumeric characters, periods, hyphens, and underscores (no spaces or slashes). This will reduce the chance that the values in the ad tag don't match the values in DFP.