\n<\/p>\n
Ever since Google threatened to eliminate third-party cookies, there\u2019s been a steady drumbeat that websites should switch to first-party data, which, many say, is better anyways. While it\u2019s definitely a good idea to collect first-party data, third-party cookies were created for a very good reason, and they still remain a useful tool that website owners should not ignore \u2014 even as they become less common and reliable.\u00a0<\/p>\n
A cookie is a small text file that a website can write to your computer. It typically includes a unique ID for each visitor \u2014 that is, for each internet browser, like Chrome or Safari.\u00a0<\/p>\n
Here\u2019s how it works. You visit a website using an internet browser. The website wants to know if you\u2019ve been there before, so it looks for the cookie on your browser. If the cookie exists, it registers you as a return visitor. If the cookie doesn\u2019t exist, it assigns you an ID and writes that to a new cookie in your browser so the site can identify you on your next page request.\u00a0<\/p>\n
Cookies are necessary because the internet was built on anonymous, stateless connections. Every time your web browser requests a page, the server sees that request as a new, anonymous visitor. The web server doesn\u2019t know if a visitor is new or if it\u2019s made 100 requests before \u2014 unless there\u2019s a cookie.\u00a0<\/p>\n
This anonymous, stateless environment made logins impossible (until cookies) because every page view was a new, anonymous request. In order to \u201cmaintain state\u201d \u2013 that is, to recognize a visitor as the same user across multiple page views \u2014 the website has to have something to identify that user. That\u2019s what the cookie does.\u00a0<\/p>\n
Right now, your internet browser probably has cookies for hundreds of websites, and on some sites, like Amazon or Gmail, that cookie might keep you logged in. If you were to delete your cookies, the next time you visited any of those sites, you\u2019d have to log in again.\u00a0<\/p>\n
Dig deeper: Alternatives to third-party\u00a0cookies<\/strong>: The state of play<\/a><\/em><\/strong><\/p>\n A first-party cookie is written to your browser by the site you\u2019re currently on. A third-party cookie is written by some other site.\u00a0<\/p>\n If I visit nationalgeographic.com, the site will write a first-party cookie to my browser that only the National Geographic servers can read. I\u2019ll also get a Doubleclick cookie. That\u2019s a third-party cookie that allows Doubleclick to identify me on any site that uses Doubleclick for ads \u2014 including NatGeo. If I browse some pages on the National Geographic site, the site\u2019s first-party cookie will allow National Geographic to track me through its site.<\/p>\n If I then go to llbean.com, the L.L. Bean first-party cookie will allow L.L. Bean to track me through its site. But Doubleclick \u2014 which I\u2019ve never visited \u2014 will track me across both sites because National Geographic and L.L. Bean both use Doubleclick\u2019s third-party cookie.\u00a0<\/p>\n The third-party cookie \u201cfollows you around,\u201d so to speak, but for good reason. By tracking a user\u2019s behavior across multiple sites, Doubleclick can create a profile of that user. For example, it will understand that he reads stories about Appalachia and looks at ads for campaign gear. That allows Doubleclick to show appropriate ads to that user on any site that uses Doubleclick for ads.\u00a0<\/p>\n Dig deeper: How one tech company is doing marketing without\u00a0cookies<\/strong><\/a><\/em><\/strong><\/p>\n First-party cookies don\u2019t follow you around. A first-party cookie is written by the site you\u2019re currently on, and can only be read by that site. That creates problems for companies with multiple websites.\u00a0<\/p>\n Let\u2019s consider ACME Dog Food Company. ACME owns 20 different websites, including feedthedogforgodssake.com (hereafter site No. 1) and wouldyoupleasefeedthedog.com (hereafter site No. 2). Each of those sites writes a first-party cookie to every browser that visits, and collects first-party data on all those visitors.\u00a0<\/p>\n The CEO of ACME Dog Food Co. wants to know how many people who visit site No. 1 also visit site No. 2, so he asks the IT manager to create such a report.\u00a0<\/p>\n The IT manager scratches his head and thinks, then he realizes that the only way he can do that is if there\u2019s some common data point that links the users between the two sites.\u00a0<\/p>\n For example, if I visit site No. 1, that site will put a site No. 1 first-party cookie in my browser, which enables site No. 1 to collect information about my visits. If I later visit site No. 2, that site will also put a first-party cookie in my browser and collect information. But there\u2019s usually nothing in either of those user records to say that it\u2019s the same person \u2014 i.e., that it\u2019s me in both cases.\u00a0<\/p>\n There are cases where such data does exist, and allows a connection to be made. If I make a purchase on both sites, the cart on each site will have collected my email address, which would enable the IT manager to tie those two records together.\u00a0\u00a0<\/p>\n Without such a common record, our bewildered IT manager is out of luck. He can\u2019t connect records between the two sites.\u00a0<\/p>\n Dig deeper: Google\u2019s Privacy Sandbox<\/strong>: What you need to know<\/a><\/em><\/strong><\/p>\n I know what you\u2019re thinking. Aren\u2019t we always hearing about how everybody\u2019s tracking us all the time, and has all this data on us? Certainly there\u2019s a way for a business to identify a common user across two sites.\u00a0<\/p>\n Unfortunately, those are two different things. The people who track most of what we do are the big companies like Google or Facebook \u2014 because they\u2019re using third-party cookies that most people have on their browsers. If you\u2019re using Chrome, your Google account follows you all over the internet.\u00a0<\/p>\n (Did you wonder why Google decided not to eliminate third-party cookies? Maybe it\u2019s because they like them too much.)\u00a0<\/p>\n What another company can collect on its own website is a different question.\u00a0<\/p>\n Having said that, yes, there are options.\u00a0<\/p>\n Remember, the problem we\u2019re trying to solve is that we have independent records on the two different sites. The solution we need is a way to find some kind of a key to match those records and merge them. Here are a few ways to do that.\u00a0<\/p>\n Here\u2019s another solution. What if ACME Dog Food Company created its own third-party cookie and implemented it on every one of ACME\u2019s websites? The cookie would create a unique ID for each visitor that would follow the visitor from site to site. That ID would become the unifying record that would allow ACME to merge user data from all of its websites.\u00a0<\/p>\n \u201cHold on,\u201d you say. \u201cThat\u2019s too simple, and it seems too good to be true.\u201d\u00a0<\/p>\n Yes, there are limitations and drawbacks.\u00a0<\/p>\n Even though Google has not eliminated third-party cookies, some other browsers have, so this technique won\u2019t work for everyone. Also, Google is (allegedly) going to allow users to opt out of third-party cookies.\u00a0<\/p>\n Given all that, let\u2019s make a pessimistic assessment and say this third-party cookie effort will only be able to match 50 percent of your users across different domains.\u00a0<\/p>\n I\u2019d say 50 percent is better than nothing, and in combination with some of the other techniques I mentioned above, you should be able to do fairly well.\u00a0<\/p>\n MarTech contributor Greg Krehbiel will be presenting a session on <\/em>Why you don\u2019t need a 360 degree view of your customer<\/a> during the Fall MarTech Conference online and free, Sept. 24\u201325.<\/em><\/p>\n <\/p>\n \n<\/div>\n Contributing authors are invited to create content for MarTech and are chosen for their expertise and contribution to the martech community. Our contributors work under the oversight of the editorial staff<\/a> and contributions are checked for quality and relevance to our readers. The opinions they express are their own.<\/em><\/p>\nFirst- and third-party cookies\u00a0<\/h2>\n
First-party cookie limitations<\/h2>\n
Wait, surely there are options\u00a0<\/h2>\n
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Or\u2026 use third-party cookies\u00a0<\/h2>\n