A guide to user-in-the-loop marketing and product work

Learn how to use simulated users to test and validate your work while it is still in progress. See how to run simulations for problem discovery, concept testing, feature prioritisation, headline and messaging tests, conversion, and findability. Fix problems while they're cheap, not after launch.

Accuracy

The predictions in these lessons were all generated by state-of-the-art Anacreon models. Anacreon predicts how individuals answer new questions, tested against data from real people.

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0.775

Ordinal alignment (industry standard)

User in the loop 11 min

Introduction to user-in-the-loop

The basics end to end. Planning simulations, running them, synthesising the results, applying the findings to version two, and planning the next round.

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Ask them

Find out what actually annoys the people you're building for Agentic problem space search 11 min

Test every choice your product could make Predictive configuration testing 7 min

Explore every way a feature could work Feature-level decision testing 5 min

Find a winning headline without the internal debate Multi-stage headline tournaments 5 min

Watch them

Beta

Discover where your competitors lose people Competitive perception modelling 9 min

Watch people try to convert before you launch Measure conversion pre-launch Coming soon

Test it with users before it's live Scan for user problems on every push Coming soon

Agents in the loop

Build a product with users in the loop Claude Code 13 min

Validate a PRD before you build it Claude web Coming soon

Build the same app twice, with and without your users Lovable Coming soon

Wire user simulation into your own stack API Coming soon

Straight answers

How accurate is this, actually Research Coming soon

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Pricing

You can’t run simulations until public Anacreon models launch in November. Get notified

Base

For one person and their agents

$139 / month

1-month free trial

Starting when Anacreon user models launch

1 seat

Unlimited simulations

4 Anacreon user modelsNov 2026 Show

US Consumer Finance
US Online Shoppers
UK Consumer Finance
UK Online Shoppers

50 more in 2027

App, MCP, API

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Org

For teams working in one workspace

$599 / month

1-month free trial

Starting when Anacreon user models launch

Base +

Unlimited seats

Shared workspace

Join the waitlist Or connect Semilattice MCP

Custom

A model of your exact audience

From

$1,799 / month

Base + Org +

Custom user model of your users

Regular working sessions and support