Chrome 80 launched February 4, 2020 with new default settings for the SameSite cookie attribute. These changes may dramatically impact third-party cookie tracking, loosely akin to Safari's ITP.
This article explains what SameSite attributes are and what you need to do as a publisher to continue monetizing your ad platform.
The SameSite attribute tells browsers when and how to fire cookies in first- or third-party situations. SameSite is used by a variety of browsers to identify whether or not to allow a cookie to be accessed.
SameSite has made headlines because Google’s Chrome 80 browser enforces a first-party default on all cookies that don’t have the attribute set. This could lead to repercussions if companies who rely on third-party cookie requests didn’t make changes by the February 4 deadline.
Sure thing! Values for the SameSite attribute include "strict", "lax", or "none":
For example, I have a social community site and I use cookie IDs to store user information. If my first-party cookies are set to "lax", I can always access that data. If my first-party cookies are set to "stric", I can’t access data if the incoming link is from an external site. For example, if a user visits my site directly from say, CNN.com, I’m unable to read the cookie.
A "stric" setting is relatively uncommon for publishers but provides greater security for financial institutions and other risk-averse companies.
Here’s an overview of the changes:
AttributeWhen cookie firesDefault modeSameSite=StrictDomain in URL bar equals the cookie’s domain (first-party) AND the link isn’t coming from a third-partyn/aSameSite=LaxDomain in URL bar equals the cookie’s domain (first-party)New default if SameSite is not set'SameSite=None'No domain limitations and third-party cookies can firePrevious default; now needs to specify 'None; Secure' for Chrome 80
It’s worth noting that ‘same company’ doesn’t equal ‘same site’. If a company owns multiple websites, cookies used across those sites would be considered cross-site (third-party) once the cookie’s domain no longer matches that of the site the user is on.
For instance, cookies used to store users’ logins, credit card numbers, and shipping addresses on Gap.com would be considered cross-site if those users click on links to Gap’s other branded sites, such as Athleta.com or BananaRepublic.com.
Specifically, Chrome now treats any cookies without the new "SameSite=None; Secure" attribute as "SameSite=Lax", which limits them to first-party contexts.
Broadly, Google’s new SameSite attribute is yet another indication of the growing concerns around data privacy. Given Chrome’s global popularity and current 63% share of the browser market, it’s also yet another push for ad tech to improve how it targets consumers and to challenge its longstanding reliance on potentially invasive third-party cookies.
Unlike Apple ITP (Intelligent Tracking Prevention), Chrome doesn't block third-party cookies by default, but it does limit their use to secure, HTTPS connections. This gives Google visibility into what cookies are third-party - opening the possibility they offer an easy future opt-out option.
If you’re a publisher, we recommend auditing, analyzing, and updating your SameSite cookie attributes to avoid diminished results and revenue in Chrome.
For more details on updating your attributes, we recommend Google's SameSite cookie recipes.
We can’t predict the future, but it’s safe to assume that third-party cookies will continue to be controversial in this age of data privacy - and continue to challenge decades-long digital advertising practices.