Latest Blogposts

Latest blog posts by Guido

Optimization hierarchy of evidence

A hierarchy of evidence (or levels of evidence) is a heuristic used to rank the relative strength of results obtained from scientific research. I've created a version of this chart/pyramid applied to CRO which you can see below. It contains the options we have as optimizers and tools and methods we often use to gather data.

View post
[EN] Datascience can do what?

This is a bonus episode with Emily Robinson (Senior Data Scientist at Warby Parker) en Lukas Vermeer (Director of Experimentation at In her earlier session that day, Emily said that real progress starts when you put your work online for others to see and comment on which in this case was about Github. Someone from the audience wondered how that works out in larger companies where a manager or even a legal department might not be overly joyous about that to say the least so I asked Emily about her thoughts on that. Recorded live with audience pre-covid-19 at the Conversion Hotel conference in november 2019 on the island of Texel in The Netherlands. (oorspronkelijk gepubliceerd op

View post
[EN] Things that are always broken in Analytics

This is a bonus episode recorded live with audience pre-covid-19 at the Conversion Hotel conference in November 2019 on the island of Texel in The Netherlands. (oorspronkelijk gepubliceerd op

View post
[EN] Building and scaling your (CRO) agency

This is a bonus episode recorded live with audience pre-covid-19 at the Conversion Hotel conference in November 2019 on the island of Texel in The Netherlands. This session is with * Stephen Pavlovich, CEO from * Daniel Markus, Co-founder at ClickValue (oorspronkelijk gepubliceerd op

View post
[EN] How you can motivate your organization to adopt CRO

Together with Ruben de Boer I explore the ways you can motivate your team and organization to adopt CRO, whether you're just starting out or already have an ongoing CRO program. (oorspronkelijk gepubliceerd op

View post
[NL] Data Bedreven Marketing

Danny Oosterveer begon ooit begonnen bij het welbekende blog Marketingfacts en is daarna parttime gaan werken als marketeer bij Burgers’ Zoo en als zelfstandige heeft hij daarnaast enkele lesprogramma’s ontwikkeld inclusief een studieboek over Digital Analytics. Hij heeft een nieuw boek geschreven dat vorige week is uitgekomen en we gaan het dan ook hebben over Data Bedreven marketing. (oorspronkelijk gepubliceerd op

View post
Are you LEFT or RIGHT brain? Surprise: you're both

You've probably heard about this divide between the functions of the Left Brain versus the Right Brain. There is no divide.

View post
The Art and Science of Converting Visitors into Customers

Khalid Saleh is CEO at Invesp, one of the first companies in North America dedicated to CRO that he founded back in 2006. He's also the co-author of an's bestselling book: "Conversion Optimization: The Art and Science of Converting Visitors into Customers, a book he published already 10 years ago. Khalid brings a ton of experience to the table and I’m glad to be talking to him today about the seemingly simple task of finding the things that are broken on your website. (oorspronkelijk gepubliceerd op

View post
Master Data Driven Business @ Hogeschool Utrecht

Ronald Voorn is Docent en onderzoeker aan de hogeschool utrecht en de universiteit twente. Hij heeft voor de hogeschool een nieuwe master ontwikkeld genaamd Data Driven Business. Ronald gaat daarmee studenten klaarstomen voor ons vakgebied en daar ben ik erg benieuwd naar! (oorspronkelijk gepubliceerd op

View post
Magento extends Magento 1 EOL

The day before Magento 1 EOL was supposed to happen, Magento decided to postpone the end!

View post
Find CRO gold using an SEO crawler

In this episode I talk with Luke Carthy and he will teach us how to use a SEO crawler to find on-site conversion bottlenecks AND you’ll find out why tea and biscuits are a golden combination... (oorspronkelijk gepubliceerd op

View post
Zoekmachine om je CRO hypotheses op psychologische theorieën te baseren

(oorspronkelijk gepubliceerd op

View post
Online Invloed

Joris Groen is psycholoog en user experience designer, gespecialiseerd in online overtuigen. Bij houdt hij zich bezig met conversie via conversational interfaces en je kent hem wellicht nog van een vorige podcast aflevering. Joris heeft een boek geschreven samen met Bas Wouters en Bas is overtuigingsexpert en oprichter van Als enige ter wereld mag hij zich Cialdini Method Certified Trainer én BJ Fogg Certified Tiny Habits coach noemen. Het boek dat de heren hebben geschreven heet Online Invloed en daar gaan we het vandaag dan ook uitgebreid over hebben! (oorspronkelijk gepubliceerd op

View post
CRO.CAFE podcast live met Tim Zuidgeest

Samen met Tim praat ik over het doen van experimenteren met je eigen offline leven en gaan we het hebben over enkele Neuromarketing fundamentals. (oorspronkelijk gepubliceerd op

View post
Holacracy: decentralized management and organizational governance

In this episode I talk with Morgan Legge, Director of Operations & Certified Partner Outreach at our long time sponsor Today is not necessarily about CRO specifically, but rather about how to work together within your company. Morgan is going to tell us about the decentralized management model called Holacracy which I personally find fascinating and we end our talk talking about how this also led to Convert applying something that is called Conscious Business by for example eliminating bias in hiring and becoming carbon positive. (oorspronkelijk gepubliceerd op

View post

I'm a cognitive psychologist focussed on E-commerce. I build teams that turn user data and insights into continuous business growth.
I speak around the world sharing my experience.

More about Guido
Keynote Speaker

In need of a keynote speaker or in-house workshop?

I speak at various international events every month and I'm regularly awarded as the best and most engaging speaker of the event. Send me your details and we'll get your event on my schedule!