+31(20) - 2617966

It's never too late
to be a rockstar

Our team

Loyalty Rockstars Customer Retention CRM Interim Team Wies Mensink

Wies Mensink

Founding Partner

Wies (1977), our founding partner, is a mom of three kids, fanatic gig-rower (Islands of Scilly), city-swimmer (Amsterdam, New York, Muiden) and kick-boxer. She had a fundamental position at the start of the renewed Bonuskaart concept of Albert Heijn. Her expertise’s are devising and creating broad customer engagement and creating loyalty concepts. She has a lot of knowledge about MarTech therefore she is able to help with the newest insights and solutions. She has a background in retail and finance. Our dedicated business developer will assist you further with your engagement and loyalty issues.

Loyalty Rockstars Customer Retention CRM Interim Team Justin Tsen Hsiang

Justin Tsen Hsiang

Founding Partner

Justin (1979) is an experienced marketer and motivated entrepreneur with years’ of experience at different companies such as Albert Heijn, Route Mobiel, Pepsico and Yourzine. In his latest function at Albert Heijn he was responsible for the datadriven personal deals within the My Bonus loyalty program. As a business consultant at Yourzine he was responsible for the new loyalty program of Rituals, Samsung and the accounts Etos and Gall & Gall. His expertise’s are target marketing, data analytics and concept development.

Loyalty Rockstars Customer Retention CRM Interim Team Niels Costerus

Niels Costerus

Senior Project Manager / IT Consultant

Niels (1977) is an avid fan of TV-series, fitness, windsurfing, sailing and good food. He is project manager and MarTech specialist, before Loyalty Rockstars he gained 10 years of experience at Telegraaf Media Groep, Cadeaukaarten Nederland and The entertainment Group. He developed e-commerce solutions for companies such as Air Miles, Shell, De Telegraaf and the Nationale Bioscoopbon. Niels lives just outside of Amsterdam and is a father of three kids.

Valérie Zeelen


Valérie (1987) started working as a consultant for Loyalty Rockstars in November 2017. She’s very enthusiastic and always open to solve new puzzles. Valérie started her career by setting up customer research, later on she consulted various oragnisations within the field of CRM & Digital marketing. She loves to help all kinds of firms by developing a customer-focused strategy, by optimizing the Customer Journey and improving marketing campaigns. Her ambitions for the future; expanding knowledge within the Customer Engagement area & learning new methods. After working hours Valérie enjoys a great meal; in a nice and trendy restaurant or home-cooked with friends.

Loyalty Rockstars Customer Retention CRM Interim Team Merel Bulder

Merel Bulder

Junior Project Manager 

Merel (1992) started at Loyalty Rockstars as a marketing trainee in 2016 and is now Junior Project Manager. She graduated Business Administration at the Rijksuniversiteit Groningen and started her Master Digital Business and Innovation at the Vrije Universiteit Amsterdam in September 2017 . During her studies she developed an interest for data analytics. The amount of knowledge from data makes her curious and enthusiastic. At Loyalty Rockstars she is focusing on data and project management. In the weekends she likes to visit restaurants. But she also loves to cook at home with friends and discover new series.

Olaf Slot

Marketing developer

Olaf (1989) started as trainee at Loyalty Rockstars in september 2017. Since february 2018 he is our parttime marketing developer. He studies Commercial Economics at the Hogeschool van Amsterdam and expects to finish in 2018. Olaf has a lot of affinity with IT, marketing and sales. At Loyalty Rockstars he wants to develop his marketing skills and use his IT background for new CRM and marketing solutions. Besides his study and job Olaf plays field-hockey with his friends, tries to go on his racing bicycle every week and he loves to cook extremely tasty food (and eating) with family and friends.