In this post:
- How view-through conversions work
- Chance, not causation
- The value of display advertising
- The “true lift” in conversions
- View-through conversion tracking
- ROI calculations
How view-through conversions work
If you advertise on the Google Display Network, there is a good chance that you know what a “view-through conversion” is. If you don’t, here’s how they work. Let’s imagine that you sell swimwear and track sales on your “Thank You” page. You’ve created a banner campaign on the Google Display Network to promote your new summer range and build awareness about your brand. Your ads show on NYTimes.com and other popular websites. A web user notices your ad on NYTimes.com but doesn’t click it. Days later, he or she returns directly to your store and buys online. The sale will appear as a view-through conversion in your Display Network campaign even though the user never interacted with your ad. View-through conversions are also known as post-impression conversions or post-view conversions.
Chance, not causation
However, view-through conversions are a controversial metric because they imply a direct causal link between the banner impression and the conversion. In practice, there are many reasons why view-through conversions may have more to do with chance than causation.
Ad networks place a cookie every time an ad loads. In practice, a single page impression can place tens of cookies on a user’s browser. For example, a single visit to the NYTimes.com homepage will save 17 third-party cookies to your browser, including 12 persistent cookies with expiration dates stretching into 2013, 2038 and 2075.
Each of these cookies will stake a claim by the ad network to a view-through conversion. However, all impressions clearly don’t convey the same value to advertisers:
- Some visitors to a page will bounce back within seconds.
- Banners that appear below the fold will generally go unnoticed.
- Banners that appear above the fold may also go unnoticed through “banner blindness”.
The value of display advertising
However, studies have shown time after time that there is value in display advertising beyond the click. Display advertising helps build brand awareness, reinforce purchase intent and can drive conversions today and over the medium term.
In 2008, Comscore assessed the impact of online display advertising on consumer behaviour. The study (Wither the Click?) showed that exposure to display advertising campaigns can bring about material changes in consumer behavior even in the absence of a click. In particular, display advertising had a positive impact on:
- Internet searches for the advertiser’s brand terms (a lift of at least 38% over a four-week period);
- Visits to the advertiser’s website (a lift of at least 46% over a four-week period);
- Online sales (27% lift on average);
- In-store sales (17% lift on average).
In short, more conversions happened across the test group over a longer period of time in the form of view-through conversions. However, conversions also happened naturally across a control group of users, virtually identical to the test group except for the test online display advertising campaign.
The “true lift” in conversions
In practice, the “true lift” in view-through conversions from your display campaigns will depend on factors that are advertiser and campaign-specific. These include:
- Brand awareness at the start of the advertising campaign. Relatively unknown brands should experience a greater lift in view-through conversions than established players with a pool of existing customers.
- The duration and reach of your display advertising campaign. The longer your campaign and the greater its frequency, the more likely people are to remember your brand and convert at a later stage.
- The purpose and type of your creative message. Ads designed to build brand awareness tend to drive more view-through conversions than direct response ads with a focus on the product or service.
- Other concurrent online and / or offline advertising campaigns. Television, radio or print advertising campaigns running at the same time will also impact your conversion volumes. Earned media – organic mentions of your brand in the media – may also impact conversions.
View-through conversion tracking
Your view-through conversion reports are likely to over-estimate the “true lift” in conversions because they imply a direct causal link between all banner impressions and subsequent conversions. However, solutions exist to keep view-through conversion volumes as close as possible to the “true lift” in conversions:
- Customize the view-through conversion window. The conversion window is the maximum number of days that you allow between the banner impression and the conversion for reporting purposes. The default conversion window is 30 days on the Google Display Network. We suggest that you align the conversion window with the buying cycle for your product or service.
- De-duplication with search. Furthermore, you should also exclude reporting for view-through conversions that are duplicated across campaigns on the Search Network and Display Network. If you enable this feature, conversions that occur through the Search Network will only be attributed to search ads. You can enable this feature with the click of a button in AdWords. However, this may be harder but not impossible to implement if you run Search and Display campaigns across distinct platforms.
We suggest that you keep view-through conversions separate from click conversions in your reports and ROI calculations. Instead, you could use view-through conversion data to focus your display campaigns on sites that generate high view-through conversion volumes in relation to their ad impressions. If website A drew twice as many view-through conversions than website B with half as many banner impressions, website A may be a far better match for your products or service. These insights could help you focus spend on this property, and/or expand your campaign across similar sites.