Free E-Books
In-depth guides to master CRO.
Free, no-email-wall guides. Real frameworks, real case studies, real D2C learnings. Including deep guides on putting AI to work in your CRO program.
Free, no-email-wall guides. Real frameworks, real case studies, real D2C learnings. Including deep guides on putting AI to work in your CRO program.
Every personalization strategy working in 2026, with examples and templates.
Sample-ratio mismatches, false positives, peeking — and what to do instead.
50+ Shopify-specific test ideas with expected lifts and sample sizes.
How AI Copilot, Wingman, and generative agents actually fit into your CRO program.
Full playbooks, not thin listicles.
By people who’ve run these experiments.
Every guide is free to download.
CustomFit e-books are free, in-depth guides — full playbooks on experimentation, personalization, pricing, and AI-driven CRO — written by operators who’ve run these programs. Practical, finishable, and free.
Pick a guide by topic.
Free PDF, no friction.
15–40 focused pages.
Run the playbook.
Deepen your program.
Level up your tactics.
A crash course in growth.
These guides are more useful than most paid courses — and they’re free.
CustomFit.ai e-booksare free, in-depth guides — full playbooks on experimentation, personalization, pricing, and AI-driven CRO — written by operators who have run these programs. They’re practical, finishable, and free to download.
Each guide goes deeper than a blog post, walking through the strategy, the experiments, and the metrics behind a specific growth lever, so your team can implement rather than just read.
Together the library is a crash course in modern D2C growth, covering testing fundamentals through advanced AI-assisted optimization.
Yes, all CustomFit guides are free to download as PDFs.
Experimentation, personalization, pricing, and AI-driven CRO, among others.
Growth, CRO, and marketing teams looking to deepen their program with practical, operator-written guidance.
Downloadable PDFs you can read anywhere and share with your team.
Most are 15–40 pages — deep enough to be useful, short enough to finish.
No. Marketers build experiments and personalized experiences in a no-code visual editor; developers can use the API and SDKs when they want deeper control.
Most teams install in minutes via a single script tag or the Shopify app and ship their first experiment the same week.
Join 2,400+ D2C brands shipping smarter experiments on CustomFit.ai.
