Identity resolution first: Why everything else in marketing comes second

A couple of months ago, I stopped by a Barnes & Noble that’s tucked into a suburban strip mall near my house. It’s a mega-brand we're all familiar with, so it wasn't something I was expecting to be surprised by. 

As I was browsing the discount section, I saw one of the cashiers, who also stocks books, call out, “Hey, Denise! We just got your new manga in — you’re up to #47, right?” She smiled, nodded, and grabbed two books without hesitation. 

All before any loyalty card was presented. No email campaign. Just this relatively new cashier, recognizing a regular and knowing exactly what would make her day. Denise also actually purchased, and didn’t just browse; if you are a bookstore afficionado like myself, that’s almost as surprising.

That mundane moment stuck with me. I work in the “identity space,” and it can mean a variety of things. But that interaction at its core was identity. “Identity” is not a complicated concept — it’s just knowing someone when you see them. Their preferences, habits, and history. 

And if even a mega-chain bookstore can keep tabs on neighborhood regulars, we are losing something if we aren’t translating that kind of consistency into enterprise-scale marketing. That’s where things get complicated — and where most brands start to fall short.

The secret to smarter marketing starts with identity 

You know the drill: You’re ready to launch a killer campaign. It’s personalized, on-brand, and multi-channel. However, the data issues begin to creep in: duplicate profiles, missing fields, and customers getting the same message twice. These issues aren’t caused by a creative or segmentation problem. They’re caused by an identity problem.

Identity is not a complicated concept — it's just knowing someone when you see them, like their preferences, habits, and history.

At Simon Data, every successful marketing strategy begins with a solid foundation in identity. Clean, connected customer data drives results and real marketing impact. That’s why we offer Simon Identity: a full-stack, marketer-friendly identity solution that puts you in control of how customer profiles are built and maintained.

Let’s talk about how we got here and why the right identity strategy might just be your most valuable marketing investment this year.

Why marketers struggle with customer data

Marketing data is messy. It comes from dozens of sources, including web behavior, e-commerce platforms, POS systems, and CRMs, and it rarely matches up. Names are formatted differently, emails are misspelled, phone numbers are incomplete, and every system has its way of tracking customers. The result? Fragmented, duplicated, inconsistent profiles that erode trust in your data.

If you’re a marketer, you’ve dealt with at least one of these headaches:

• You’re not sure which customer profile is the “real” one
• You’ve sent duplicate messages because the same person exists in multiple places
• You’re dependent on technical teams to fix identity issues
• Your AI tools can’t perform well because the data they're learning from is unreliable

When identity is broken, every part of the marketing stack suffers. Personalization feels off. Segments are shaky. ROI takes a hit. The longer it goes unresolved, the harder it becomes to fix.

What makes Simon Data different?

Other platforms treat identity like a black box: either you trust their process, or you don’t.

When identity is broken, every part of the marketing stack suffers. Personalization feels off. Segments are shaky. ROI takes a hit.

Simon takes a different approach: not only do we give marketers the tools they need to take control, we also provide real human support for the most crucial stages.

Here’s the process:

1. Entity Resolution

Entity resolution is the data-cleanup phase that normalizes, deduplicates, and cleanses incoming data before it even gets used in profile stitching. It’s the foundation of a trustworthy identity.

It’s also where we have a team of dedicated Identity Architects (that’s me, btw) to help. Just getting to this stage can mean a lot of effort for your internal team: determining which data sources you want to bring in, selecting a stable ID for your customer profiles, weighing different edge-case merge rules. If any of these sound like a headache, know that we have real human support to advise on (or drive) the whole thing. 

2. Identity Resolution

This is where the magic happens. We connect the dots across disconnected data points to create a single, unified view of the customer. It’s your Customer 360, done right.

There isn’t any magic, for the record. Remember: no black boxes! The rules we use to combine your customer records have default recommendations, but they are also fully transparent and customizable. Ideally, everything relies on that one, agreed-upon stable ID, but that doesn’t always fit every business.

3. Advanced Survivorship

This one’s a relief if you have ever experienced poor attempts at identity in the past. 

Survivorship rules determine which data “wins” when two records are merged. With Simon, you can set field-level rules like “prefer the most recent email” or “aggregate purchase history.” 

It’s all customizable, and every decision is logged with complete transparency. And while our Identity team is here to advise you on best practices here, the tools remain entirely accessible to you, alongside everything else in the Simon Data app.

4. Self-Serve Identity Model Management

Do you need to reference the identity model rules you set up? What might a change do to your data? Go for it — with no engineering ticket required. Marketers can configure, test, and analyze identity models independently. Compare them against the current version, get full audit trails, and iterate as needed.

5. Units & Identity+

This is where the definition of “identity” can start to wander a bit, but I’m here for it. With steps 1-4, you can consistently identify and segment customers who provide their details (when they make a purchase, log in to your site, etc.). Awesome, and this is where you could stop and accurately say you have identity handled.

… but what about things they don’t tell you? 

Enrich+

Going back to the Barnes & Noble example, if a customer walks into your shop, you make an educated guess about their preference based on their appearance. On the enterprise scale, you don’t just want to know what they’ve told you, but also what they haven’t. Gender, age, and income estimates are all key pieces of segmenting prospective shoppers, and they are things you don’t often have in your customer profile.

Enrich+ is Simon Data’s way of addressing that gap: let us know which demographic elements are helpful in your business, and we will provide them on your customer profiles. Perfect for segmentation, and all seamlessly integrated.

Identity+ 

How about when your customer is browsing your store, but you don’t recognize them as a customer, since they haven’t logged in? There’s a ton of missed potential here, especially when they abandon their cart, and you could be sending them an email about it, if only you recognized them as an existing customer for whom you have an email address on file.

Enter Identity+, Simon Data’s way of providing an ID for customers browsing your site that ties right back to your customer data. It’s the identity model you have already created, just amplified. 

Not to bore you with the details (there are detailed docs, if you’re curious), but we leverage a partnership with a major publishing network to identify browsers who subscribe to most major newsletters/emails, and from there connect them to your customer data. Pretty amazing, and most importantly, already consented to and expected by your existing customers.

Match+

Lastly, what about when your customer leaves you an email or phone number, only for it to be completely different from the one they use for their social media browsing? Normally, this would make it impossible to find them, and if it wasn’t their primary email, good luck getting messages to them effectively! 

With Simon Data,  Match+ enriches your first-party data by adding additional hashed email addresses (HEMs) and mobile ad IDs (MAIDs), increasing your ability to match customers across various advertising platforms and leading to higher match rates and improved return on ad spend (ROAS).

For instance, brands have seen match rate lifts of up to 43% on platforms like Meta after implementing Match+ . By expanding your reach and improving targeting accuracy, Match+ helps ensure that your marketing messages reach the maximum audience they can connect with.

Why this matters, especially for AI

Let’s talk about the elephant in every modern marketing room: artificial intelligence. AI promises incredible things: predictive segmentation, personalized experiences at scale, next-best-action recommendations… but it’s only as good as the data you feed it. 

And if your customer profiles are messy or duplicated? AI is likely to learn incorrect information, make inaccurate predictions, and negatively impact your performance.

Simon Identity makes sure your AI gets the right foundation:

• Clean, deduplicated profiles so customer behavior is clear
• Custom survivorship rules that highlight the most relevant data
• Transparent identity resolution, so you know exactly how the data was created
  

Bottom line? Better identity = better AI = better results.

Who benefits? (Spoiler: Everyone). We designed Simon Identity with a wide range of users in mind. Here’s how it helps across the organization:

For marketing leaders

• Launch campaigns with confidence, knowing your data is clean
• Define business-specific rules for how customer profiles are built
• Build segments and personalizations on accurate, unified profiles
  Understand your identity models without relying on engineers

For the C-suite

• Cut wasted spend caused by duplicate or inaccurate profiles
• Build brand trust through consistent customer experiences
• Lay the groundwork for scalable AI success
• Enable marketing to move faster without creating technical debt

For technical teams

• Reduce the backlog of identity-related requests
• Maintain full visibility with audit trails and compliance tools
• Seamlessly integrate with existing data infrastructure
• Empower business users while keeping enterprise-grade standards

How retailers use Simon Data for Identity

Let’s say you’re a retail brand with both ecommerce and in-store data. Without strong identity resolution, you might have the same customer listed three times, once from a website order, once from a loyalty program, and once from an in-store receipt. That means three email records, three addresses, and potentially three totally different “personas.”

With Simon Data, you can unify all that data using rules that match your business needs. Want to prioritize primary email addresses? Done. Aggregate lifetime value across brands? Easy. Use the most recent shipping address for direct mail? You got it. And you’ll always know exactly why a profile was merged.

Get started with Simon Identity today

Identity used to be the domain of IT. Today, it's a strategic advantage for marketers, especially as AI, privacy rules, and data complexity continue to evolve. If you don’t have control over your identity strategy, you’re flying blind.

AI promises incredible things... but it's only as good as the data you feed it. And if your customer profiles are messy or duplicated? AI is likely to learn incorrect information, make inaccurate predictions, and negatively impact your performance.

With Simon’s approach to identity, you’re not just getting another tool. You’re getting a marketer-first, future-proof solution that:

• Cleans and connects your customer data
• Gives you complete control and transparency
• Powers the AI and personalization tools that drive growth

So if you're tired of second-guessing your data, fighting with engineering tickets, or wondering why your campaigns aren't hitting the mark, it’s time to fix your foundation.

Because in modern marketing, everything starts with identity.