Mobile Tutorial Series – Why Do They Say Cookies Don’t Work in Mobile?

By John Koetsier January 1, 2017

When the subject of customer data arises, you’ll frequently hear the statement “cookies don’t work in mobile.” This post is designed to explain why people say that, and the alternative approaches for collecting and interpreting customer behavior on the mobile web and in apps.

What are Third-Party Cookies

Third-party cookies have long been the workhorses of PC web tracking. A cookie is a small text file placed on your computer when you view content and webpages online. Third-party cookies are frequently used by advertisers to help understand how consumers act after they are exposed to online ads. Some examples:

When a Person Sees an Ad and Clicks: Third-party cookies enable advertisers to track post-click actions and associate them with the marketing activity that drove them.
When a Person Sees an Ad and Doesn’t Click: Often people don’t click on an ad when they see it, but do follow up hours or days later and visit the advertiser’s site directly. Here the third-party cookie can also measure the consumer’s actions post-ad-exposure. We call this view-through measurement.

Typically, third-party cookies have a pre-set expiry date, usually from twenty-four hours to thirty days after an exposure. If a user sees an advertiser’s message on one day and then another ad on another day, the expiry is reset to zero and the time is counted from the second exposure.

Third-party cookies help advertisers understand the effects of their marketing by passing back non-personally identifiable information about user behavior after an ad exposure. In addition, media companies use third-party cookies to infer interests of web users by analyzing the content and web pages an anonymized user visits online. Lots of visits to an auto site, for example, are a pretty good indicator that someone is in market for a car.

To offer consumers privacy and choice options, reputable media companies enable people to opt-in or opt-out of third party cookie tracking. Consumers can also control ad tracking by periodically clearing cookies on their browsers. Some browsers now also offer simple toggle switches to turn third-party tracking on or off.

Third-Party Cookies and Mobile

In order to understand how third-party cookies work (and don’t work) in mobile, we need to draw a distinction between the mobile web and mobile apps. The mobile web refers to using a browser to visit sites and content on a mobile phone. For example, when you tap the Safari icon on your iPhone or a Chrome icon on your Android phone. Mobile apps are separate experiences optimized for the mobile device and screen. You access apps by tapping their specific icons, not by opening a browser and visiting web pages.

Third-Party Cookies and the Mobile Web

Acceptance of third-party cookies varies by mobile browser, but since Apple’s Safari and Google’s Chrome are by far the most common browsers, we’ll limit our discussion to these. By default, Safari blocks third-party cookies, so activities of Safari users on the mobile web cannot be collected and interpreted unless the consumer turns cookie blocking off in their settings. While click-based conversions can be tracked, activity other than what happens after an immediate click cannot.

Google’s Chrome does not block third-party cookies by default, so such cookies can be used for tracking on the mobile web. Chrome users have the option of turning on cookie blocking in their settings.

Because Apple and Safari dominate mobile browsing (in the US,) and because many consumers are deleting cookies periodically from their Google Android devices, tracking mobile web activity with cookies leaves significant holes in your data.

Third-Party Cookies and Mobile Apps

Mobile apps are downloaded by the user, or come bundled with their phone. Third-party cookies cannot provide an adequate source of in-app data. Every app is a separate environment on a phone, with little or no data sharing allowed across apps. Further, both Google and Apple have purposely prevented third-party cookie efficacy, preferring that advertisers track using a mobile advertising ID instead.

A Better Alternative for Mobile Tracking and Analytics

Companies that are serious about understanding customer actions on mobile work with a mobile app and attribution and analytics company like Singular. Most such partners use an SDK that the brand places in their apps to enable tracking, regardless of browser or operating system.

By collecting mobile data in this manner and combining it with other first party data sources, brands can create more complete customer profiles to enable more effective marketing.

Download The Singular ROI Index to see the world’s first ranking of ad networks by app ROI.


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