Trainer / consultant / lead for
conversion optimization (CRO),
digital experimentation and A/B-testing

Consulting | Training | Speaking | Community

Specialist in Conversion Optimization and Digital Experimentation

I love to work with organizations on conversion optimization projects. Securing optimization and experimentation in the DNA of teams and organizations gets me up in the morning. It's an extensive range of work that I like: from the broad strategic perspective on the one hand to the nitty-gritty details of user growth opportunities within digital channels on the other hand. Ultimately, it's all about solving problems, which I do fast and effectively based on data.Dive into my projects & testimonials

Work with me? Use the contact form to reach out!

Conversion Optimization and Digital Experimentation projects & testimonials

Since 2006 I've helped over 50 organizations with their conversion optimization challenges. My CRO work experience ranges from travel to retail and publishing to government. I have been working with local and international clients, from scale-ups to enterprise organizations, from digital-first to digitally "not yet transformed".Over the years, I have created conversion agencies, conversion-related websites and tools, conversion training courses, and conversion events. My main love for the conversion optimization and experimentation industry never changed to something else than the actual work itself. This mindset also keeps me from ending up as a conversion professor that has not been doing real CRO work for over 10 years...

Recent or ongoing projects:✓ Advising a new ticket marketplace on getting the basic CRO principles right
✓ Interviewing experimentation teams for the Experimentation Culture Awards
✓ Advising a European Ecommerce Platform on their Experimentation Program
✓ Reviewing the experimentation process at a large US publisher
✓ Creating A/B-test courses for several e-learning platforms

My current daily work is running conversion-related webinars/events for the optimizers community, which I combine with actual CRO and experimentation-related work on a contract / project basis. I'm not involved in the daily operations of the Conversion agencies I founded.

Examples of projects I've finished successfully in the past:✓ Travel company (NL): leading the project to set up CRO in the organization
✓ Publisher (EU): training teams on experimentation and persuasion tactics
✓ Telecom company (EU): consulting on CRO projects at several offices
✓ Ecommerce company (NL): leading the check-out funnel CRO project
✓ Banking (NL): training teams to become more effective in CRO

Work with me? Use the contact form to reach out!

Workshops, masterclasses and online training about CRO and A/B-testing

Frequently I host Conversion Optimization and A/B-testing masterclasses and workshops, mostly co-organized with Conversion Optimization related industry events.I'm also available for in-house training: live and remote.

I've created the following virtual courses:✓ A/B-testing mastery for CXL Institute in the US
✓ A/B-testing deep dive for Emerce in the Netherlands
✓ A/B-testing success for the Digital Elite Hub in the UK

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Keynote speaker on Conversion Optimization and Digital Experimentation

As an experienced optimization specialist, I'm often invited to present my knowledge and learnings on experimentation culture, conversion optimization, and a/b-testing at conferences around the (virtual) world.

I was invited to keynote at events like:✓ Experimentation Elite in the United Kingdom
✓ Emerce Conversion in The Netherlands
✓ Conversion Jam in Sweden and Norway
✓ Growth Marketing Summit in Germany
✓ Digital Elite Camp in Estonia
✓ CXL Live in the United States
✓ Conversion Boost in Denmark
✓ Superweek in Hungary
I'm also available for in-company presentations (and workshops), where I was hired before by companies like:, Heineken, Rabobank and RTL.

Work with me? Use the contact form to reach out!

Helping the Optimizers Community to get to a higher level of professionalism

Evidence-based growth is a fascinating way of working. I've always seen conversion optimization, digital experimentation, and A/B-testing as the correct methodology for business success. It brings proven results and fun to organizations and teams.The CRO industry always deserves more attention and will receive this if we keep growing to higher maturity levels. This is why I'm organizing events like Conversion Hotel and the Experimentation Culture Awards and why I am publishing tools like ABtestguide.Visit the websites for tickets and sponsorship opportunities.

The full overview of the industry event and publishing activities I started can be found on my Holding company website.Work with me? Use the contact form to reach out!

Contact form

Please use this form to send me a message. Feel free to reach out for consultancy, training, or speaking opportunities on CRO, Experimentation, and A/B-testing. You can book a 30-minute introduction videocall directly through this link.

You can also abuse the form below for questions on the courses I'm running and for speaking and/or sponsor opportunities for my event and publishing activities like Conversion Hotel and the Experimentation Culture Awards. Just reach out!

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Speaker profile

Name: Ton WesselingCountry: The NetherlandsTitle: Evidence-based growth expert or Experimentation Evangelist (depending on the topic of the presentation).Subtitle: Founder of Online Dialogue, Conversion Hotel, and The Experimentation Culture AwardsLegend of Experimentation 2023 award winner (Experimentation Elite)Linkedin: website: https://tonw.comDescription:
I help organizations to become more successful by adopting a solid experimentation and validation approach.
I've worked in this industry for over 20 years and still love it. Experimentation brings answers and joy; it's a key driver for growth.I've started agencies, websites, and tools in this field, written many articles, and created training courses and events.My main love never changed to something other than the optimization work itself, and I've now happily consulted over 50 organizations in 10 different countries.Eat, sleep, experiment, repeat.

Speaker pictures

True Discovery Rate Matrix

A True Discovery Rate Matrix for understanding how many significant positive A/B-testing outcomes are NOT false positives.This is the full size image from this Linkedin post about FDR / TDR.You can use this calculator to calculate your True Disovery rate.Find your True Discovery Rate based on 80% Power (1-sided testing) in the matrix below. Your significance threshold is on the X-axis, and your win percentage is on the Y-axis. Stay on the right of the blue line!

Landing page competition

I was invited to participate in the landing page competition for CROday 2016. A landing page for a fake product was created by Unbouce and I was given the task to optimize this landing page. Goal was to have the most right answers given by a panel through a 5-second test.There were some interesting lessons learned along this journey which I shared with the attendees on CROday. You will find these lessons here:

Tracking consent overview