Dear supermarket, part 2.

by Dries De Roeck on February 1, 2017

Remember that time I requested my personal data collected by my supermarket? I think I owe society an update, since the whole story ended rather positively compared to what the previous post might suggest.


After sending a registered letter to my supermarket, stating clearly that I was requesting my data as a natural person, I got sent a pile of paper with all my purchases since 2006. Check out a sample here.

Where were we?

Let’s recap the goal first. I thought it would be a nice experiment to see how easy it would be to request a copy of my personal data kept by the supermarket I frequent most.

The previous part to this story ended in the more philosophical explanation why I wanted to go through all the hassle, being an attempt to build my personal API. In the same post, I concluded rather negatively. I went through quite a bit of communication with my supermarket’s customer service, which initially resulted in some miscommunication from my end related to requesting info as a natural person.

The registered letter

As the communication through email was rather sluggish, I decided to spark the fire by sending a registered letter. In this letter, I very clearly stated my request, focussing on:

  • I was requesting this information as a natural person
  • I was mostly interested in my historical purchase data
  • I included a separate (new) request for a copy of my personal data and included a copy of my (Belgian) passport.

In this letter, I also referred to the European legislation on data privacy. I was somewhat lucky that at the time of sending the letter, the legislation just went through a significant update – making it more clear how personal data should be treated from a European point of view. For completeness, a copy of the letters I sent can be found here.

The reply!

Not that long after I sent the registered letter, I received a large brown enveloppe through the mail, containing all my purchase data at my supermarket from 2011 onwards. This data included a full detail of all my purchases, item names, prices, where I shopped, how much I spent in total, etc.

Check out a sample of the data here.

In the end, I was really happy with how this turned out. Looking back, this has been an extremely educative journey. I got to understand privacy law a little better, learned that this piece of legislation mostly applies to natural persons and developed a better sense for data privacy overall.

And now?

I received the data at the start of┬áthe summer holidays, and haven’t done anything with it since. This is mostly because my initial attempts at OCR-ing the scanned data turned out to be harder than I thought. Initially, I wanted to contact my supermarket again to request a digital copy – but figured that they were probably sending me the data on paper for some purpose.

At the moment, I’m regarding the OCR process as a next challenge. Once that is done, I hope to build some kind of ‘Feltron report inspired’ dashboard of my supermarket purchase behaviour. But since the whole data processing and visualising is all very new to me, it is taking me some time to understand what I’m doing. Watch this space.

Some closing thoughts

Looking back this process started by reading the privacy charter of Colruyt group. Since they make explicit mention of data privacy, I would have expected my request to be handled a lot faster. @Colruytgroup some suggestions :

  • Be more clear in communication. I had the feeling the customer service person was being treated as someone who had to clean up the dirty work. One email I got included a copy paste out of another (internal) email, which was not friendly at all. My current understanding of the situation is that the online customer service does not really know how to handle requests like this, which slows down communication terribly.
  • Don’t send me paper. In the pile of paper I received, there were a couple of pages of screenshots out of internal Colruyt software. This forces me to believe that the internal software is unable to export data to a more universal format. Also, I wonder why I received all data printed on paper in the first place. I didn’t explicitly request a digital copy, for sure, but knowing that Colruyt greatly values the environment, it surprised me to receive a pile of processed trees.
  • Transparency. What I love about Colruyt is the transparency towards customers. Prices in shops are constantly updated, comparisons are made with other supermarkets in the area, etc. Suppose that the organisation could push this level of transparency through to a personal level, by ideally giving everyone access to a personal data portal or similar, would set a clear example for others on a national and international scale. Although this might be a utopia, it would clearly show that you, as a supermarket, deeply respect your customers.

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