51Did is an identifier you can actually check. Check what it does inside your own business, and what changes when it travels.
Almost every digital advertising identifier on the web arrives in a request, gets read, and is assumed genuine by everybody downstream.
Very few challenge it, and most of the time nobody gets hurt. It matters when somebody takes advantage, because a copied identifier behaves exactly like a real one. It is real. That is the problem. It was issued properly. It just is not being used by the visitor it was created for.
51Did is our answer, and it launches this month. This is the plain English version. No code, no diagrams. If you are technical, the documentation goes considerably deeper.
What is a 51Did?
It is an identifier for a website visitor, short for 51Degrees Identifier. It lets you tell one visitor from another and recognize the same one when they come back. Nothing else.
Inside a 51Did sits a match key, which can be used with one of three different types of identifier:
- Probabilistic, the one this blog is mostly about, is worked out from the device and the connection the visit arrives on.
- Random is a unique value with no ingredients at all, for when you want a label that means something to you and nothing to anybody else.
- Hashed Email, or HEM, is built from an email address a visitor has given you, scrambled so the address itself never travels.
Same wrapper, same checks, three starting points.
Two things make all three useful.
The Probabilistic identifier is worked out from Device Detection and IP Intelligence insights, so the same device, operating system and browser on the same connection gets the same identifier.
And we sign all three types of identifiers. Anyone receiving a 51Did can check that it is genuine, and that the context it was created in has not changed, meaning the device, the browser and the connection.
Keep reading to see what you can do with a 51Did.
Is this the same visitor?
Most companies need to know this, and do not realize there is a simple answer.
You run a website and you want answers to questions that sound trivial but are not. Is this the visitor who was here yesterday? Is this the device that just tried nine different card numbers at your checkout? Are these three hundred sessions likely to be three hundred people, or a script?
You can use first-party cookies, but what has changed is how much of your traffic they still cover. A cookie only exists after you set one, so it tells you nothing about the visit where you actually needed it most. Browsers clear cookies far more aggressively than they used to, and fraudsters clear them on purpose between attempts.
This is not a cookie replacement. This is the 51Did used internally, the plainest version of the product. You ask our Cloud for an identifier, tell us it is for non-marketing purposes, meaning analytics, fraud and security, and use it inside your own systems. It does not go into a bid request, and it is not shared with third parties.
Which type you use depends on what you hold. Have an email address, use HEM. Only need your own opaque label, use Random. Neither, which is most of your traffic, use Probabilistic.
Managing marketing preferences
Outside your own systems, a 51Did carries a visitor's marketing preferences across the advertising chain.
A publisher puts one script on the page, and the visitor gets a straight question: how would you like your access to this site paid for? Personalized advertising, standard advertising, or a paid alternative such as a subscription. Three options, asked once. The answer is carried by the identifier itself, and it goes wherever the identifier goes. The 51Did can also be used with your existing CMP solution.
An identifier used to sell advertising is a different proposition from one used to count sessions, and it ought to be treated as one, because it is transmitting information across different organizations, potentially invoking a range of legislation and guidance.
In this use case the 51Did is protected by the Model Terms for Marketing (MTM), not by encryption. The MTM mean that users of a 51Did have no legal means of reidentifying a user. This protection is contractual and means that a 51Did is not personal data and so is not subject to data protection law. Every party that receives one must be bound by the same terms.
A 51Did does not carry IDs or other data a publisher has taken from a user's device. That stays with the publisher, under the legal basis the publisher used.
Used this way, a 51Did provides:
- a timestamp, a record of when it was created
- the embedded permission, the Model Terms inside the identifier itself
- creator attestation, proof of who issued it and that it is genuine
- creator context verification, proof of whether the original device, browser or connection has changed
The last two protect against fraud and identify invalid traffic.
One identifier, three product options
51Degrees Match Keys, for any website. Create identifiers and tag your own traffic. Repeat visitors, suspicious devices, real session counts. No marketing terms, because nothing leaves your building.
51Degrees Preference Manager, for publishers. Ask readers how they want their access funded and label the traffic to match, adding value to advertisers by making traffic addressable with a rich identifier. One script on the page, creating and validating 51Dids, and can work with the existing CMP and TCF setup you already have.
51Degrees Validator, for SSPs, DSPs, agencies, and advertisers. Check what arrives in your bid stream or click. Is it genuine, and used where it was created? With 51Did you can more effectively personalize your advertising safe in the knowledge that data protection is not an issue.
All three run on 51Degrees Cloud or On-premise.
Where to start
If you want to tag your own traffic, the non-marketing version is the quickest and can be running in minutes. For Preference Management and in the bid stream, contact us at 51Degrees so we can get you started.