There is quite a bit of debate going on about people based matching versus cookie based matching. I thought that I’d take a minute to set the record straight.
Before I start, it’s important to have a basic knowledge of how the Internet and cookies work together.
WHAT IS A COOKIE?
A cookie is actually just a small text file, which sits on your device (like a laptop, a tablet, or a mobile phone). Your device can store countless cookies from the various websites you’ve visited, and each is unique to your device and in some cases your web browser.
Cookies are used to store information about your web browsing. This information could be your name (so that the webpage can greet you … eg: “Welcome back Scott”, address, your username / password (to give you access to a specific website), the web pages that you’ve visited before, etc.
Now to understand the importance of a cookie, you need to understand how a web server works.
THE WEB SERVERS AND COOKIES IN BASIC TERMS
Imagine you’re at a hotel bar, and you’re charging drinks to your room. Each time you go up to the bar for a refill, you have to repeat your room number because the bartender has a really bad memory. Now imagine that the bartender can look up your room number using your room key.
This is how the Web Servers and cookies work together.
Websites are hosted on Web Servers. When you surf the web, each webpage is delivered to your device (phone, ipad, etc.) from the Web Server independently. The Web Server is a “session state” environment, meaning that it cannot natively associate one request from a device to another. In other words, it only “sees” (and remembers) each webpage request separately. This is where cookies come in. They help carry information to the Web Server, from one webpage request to another.
In the example above, you are the web browser. The bartender is the Web Server. The drink you order is the web page. And your room key is the Cookie.
Cookies can also be used to target advertising. An Ad Server (like a Web Server for advertisements) can be programmed to serve specific ads to specific cookies. This is the technology used to deliver ads to specific people.
THE PROBLEM WITH COOKIES
A cookie, in and of itself, isn’t the problem. The problem is the linkage. How was a cookie associated with the person to whom the ad is being served. As marketers, we need to make sure that we are reaching the right people with the right ad … and more importantly not reaching those people who have opted out.
This is especially true in the world of regulated data, where you need to know who you are targeting. And cookie-based linkage is controlled by a handful of companies who 1) are walled gardens and don’t share how they link offline people to online cookies 2) they don’t collect this information directly. They rely on other websites to gather PII, and connect it to their cookies. In some cases, the data is very accurate (especially with transaction data). In some cases, it is not (think websites that collect PII when giving surveys, offering coupons, etc.).