Zero-Party Data =/= A Party ☹️

Lindsey Coulter
Founder
June 29, 2025

Zero-party data collection and quizzes are a big buzzword in the retention community and are constantly posted about on LinkedIn. It's like they're some magical potion to increase conversions with no other changes, and everyone is supposed to know what it means.

For those unfamiliar, zero-party data refers to data voluntarily given to a brand/company. It includes email, phone number, personal details like size, preference, or unique data points specific to a product. The most common example is 'quizzes.'

And, for the marketers wanting to know the difference, first-party data relates to data collected from interactions. Think email opens, clicks, cart abandonment, website activity, etc. Essentially, those cookies everybody warned you about.

So, do they work?

After deploying 100s of opt-in quizzes and zero-party data opt-in flows, here's the deal: They don't work for everyone and require lots of data to justify.

They work well for:

  • Health and beauty
    • After reviewing hundreds of tests from various brands, health and beauty are very personal products that typically solve a personal issue or concern. In most SKU catalogs in this vertical, there are different choices for different areas, and this helps guide consumers down the right path to conversion. Big win in this space with noticeable lift.
  • Parents + Children's Brands
    • They worked exceptionally well for brands related to children targeted toward parents. One of our most successful ZPD flows was for a children's health supplement company. This audience responds heavily to education and loves the associated information.
  • Large SKU stores
    • ZPD works well to alleviate decision anxiety. The subsequent messages through email/sms can guide them through large SKU catalogs and categories and help them find what they need with fewer clicks.
  • Specialized hobby niche stores
    • As an example, there's a store that specifically makes accessories and clothing for people in the trades. We found that asking them what trade they were in and merchandising to their specialty created a significant lift in both campaigns and flows.
  • Pets
    • Similar to parents and children's shopping, pet verticals perform exceptionally well with ZPD and personalization. One of the better ones that comes to mind is The Farmer's Dog.

Jury's out on:

  • Location-based selections and products
    • While it makes collection easier, there's little data that points to it increasing conversions in the short or long term, it just makes targeting easier for campaigns that relate to those areas. In my opinion, first-party data is a better segmentation tool than zero-party data in these scenarios.

They perform poorly for:

  • Low SKU catalogs with simple use/problem products
    • People searched for the thing, whatever it is, and they just need to make sure it aligns with the problem they're looking to solve and does so effectively. They don't need education on, let's say, a phone case. What options would you even give? I'm interested in: 'Protection' 'Self-expression' 'Expressive Protection'??
  • CPG.
    • When you remove health CPG (protein powders, health related items), CPG quizzes did not make a meaningful lift in any metrics, and in some cases, actually lowered in some areas. CPG shopping behavior is different than standard e-commerce. We find many users come from in-store activation vs. onsite, further disconnecting the buying journey. I think natively (and only) online CPG has some promise, but none showed enough to justify keeping it or using it long term.

Are they Inbox Stars approved?

Definitely recommend it for the ~$8m+ annual revenue group. This is not a significant revenue driver for a small brand and does not move the needle. With a testing plan, healthy enough traffic for significant data and clear baseline, they unlock a lot of great opportunities that do create lift.

It can be easy to implement and see certain numbers go up (think clicks, opens, even conversion on personalized emails), but if aggregate conversions are lower compared to baseline than you're making... less money.

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