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Email Ads And The User ID Macro

Read time: 5 minutes

Key Takeaways

  • Email ad serving is similar to web ads: You still have banners, campaigns, channels, assignments, and zone tags.

  • Image-only banners: Due to email limitations, scripts and iframes aren’t allowed, so only images can be served.

  • User tracking needs a macro: The Email User ID Macro uniquely identifies each email, allowing AdButler to track impressions, clicks, and destinations accurately.

  • Cache-busting for email providers: Large services like Gmail need the macro to treat each banner as unique, avoiding duplicate caching for multiple recipients.

  • Macros are provider-specific: Your email service (e.g., MailChimp) generates the macro, which is automatically unique per email.

  • Critical for advanced functionality: Without the macro, AdButler can’t serve multiple banners from the same zone or properly attribute clicks to impressions.

Serving email ads with AdButler is almost exactly the same as any other ad serving we do. There are banners, campaigns, channels, assignments, and almost all of the other great features you’d expect. We even have the same zone tag button. Only when you hit it, you see something a bit different.

The Email User ID Macro. Which we need your help generating, even if you don’t know what it is.

To get it out of the way: The Email User ID Macro is a macro provided by your email service that generates a unique string for every email sent. We use the string as an unique identifier for each email banner, letting us properly record statistics.

If this is your first time serving email banners, or if you haven’t done it in a while, you might not realize you need a User ID Macro. And that’s okay. Even if you know what it is and where to put it, it might be a mystery why you need it. Can’t AdButler tell each banner is unique by itself, anyways?

Well, we wish it could. But it’s a drawback (or feature) of how email works. There are three distinct limitations when comparing email ad serving to normal ad serving: you can’t run scripts, you can only serve image banners, and you can’t tell who’s looking at the email. Let’s go over these.

To get around not being able to run scripts, AdButler uses only pure HTML and CSS to serve banners. And to get around only serving images, well, you can only serve image banners. No iframes, no inline Javascript. Only images. Pretty simple solutions.

The third limitation is where the Email User ID Macro comes in. When a banner is served, ad servers usually look at the requestor to get all the unique information that identifies that person: where they are, what time it is, if they’ve clicked, etc. We still get that information with an email banner, but with one key difference: no scripts. Because there aren’t any scripts, we suddenly can’t tie any clicks and impressions together. Even worse, we can’t tie clicks with their destinations, so if someone clicks on the banner it won’t go where it’s suppose to. In other words, although we’re serving both an image and a link, we have no way of knowing they’re being served together.

The User ID Macro is our solution. Suddenly we can tell if someone clicks a banner or not, and where to send them. It also allows us to serve different banners from the same zone – two non-trivial things. The macro also serves as a cache buster for larger services, like Gmail. If we didn’t have it Google would try and serve one copy of the banner to everyone it was sent to, making it impossible to identify unique clicks. By adding in the User ID Macro, Google recognizes each banner as being unique and gives each email a personal copy as opposed to a generic one. The Email User ID Macro is incredibly important, and our entire email banner system revolves around it. We’re saved by it.

So that’s the ‘why’ of it, but where’s the ‘what’? An Email User ID Macro is something your email marketing service, like MailChimp, can provide. It uses your service’s macros and information to generate some ID that is unique to that very email. Generally, it is something that can never repeat, such as that email’s identifier mixed with the identifier for who it’s being sent to (in MailChimp, that’s *|CAMPAIGN_UID|**|UNIQID|*). The important aspect of the User ID is that it can’t be manually set. You have to use a macro, because your email provider has to be able to generate it on the fly for all 1,000 or 10,000, however many emails you send out.

The Email User ID Macro is the backbone to our email system. Without it, we would be stuck. If you’re not sure how to generate it, try contacting your provider. They should be able to help you out. Or contact our great support. They’re always there for you!

FAQs

Why do I need an Email User ID Macro?

Emails don’t support scripts, and each banner is just an image. The macro allows AdButler to identify each individual email, track clicks, and send users to the right destination. It also helps serve multiple banners from the same zone without confusion.

Can I manually set the User ID Macro?

No. The macro must be generated by your email service. It’s unique for each email and created on the fly, ensuring no duplicates across thousands of recipients.

Which email services provide this macro?

Most major email marketing platforms, like MailChimp, provide macros. For example, MailChimp uses *|CAMPAIGN_UID|**|UNIQID|* to create a unique identifier for each email.

How does the macro help with Gmail or other large providers?

The macro acts as a cache buster. Without it, Gmail may serve a single copy of the banner to all recipients, preventing proper click and impression tracking. With the macro, every email is treated as unique.

What happens if I don’t use the macro?

Without it, AdButler can’t match clicks to impressions, can’t serve different banners from the same zone, and won’t be able to track which users engaged with the email. Essentially, you lose all accurate reporting for your email campaign.

I’m not sure how to generate the macro. What should I do?

Contact your email service provider—they can guide you on the correct macro for your platform. If needed, AdButler support can help ensure it’s implemented correctly.


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