- Grab a Super+ loyalty card leaflet + card.
- Lift the card just enough to reveal the barcode and scan the barcode; OR alternatively lift it a little more to reveal the digits and photograph them when no one is looking of course… and leave it on the top of the stack. Otherwise bring the leaflet home.
- From home, run these commands on your Debian machine:
$ sudo aptitude install barcode; # or use apt if you prefer
$ barcode -b "$delhaize_barcode" -e upc -E -p A8 | epstopdf --filter > /tmp/delhaize_super+.pdf; # where "$delhaize_barcode" is the unique 12-digit code you grabbed.
$ sudo adb start-server; # if this fails, skip the next 2 commands. Otherwise connect your phone to the Debian machine over USB before the next step
$ adb shell mkdir storage/sdcard1/my_disloyalty_cards
$ adb push /tmp/delhaize_super+.pdf storage/sdcard1/my_disloyalty_cards/
- If you took the leaflet and card home, then your final step is to return to Delhaize and sneak it onto the top of the pile. Eventually someone else will take the card home and activate it by registering it in their name.
No worries if the last 3 “adb” developer commands fail. They will likely fail for most people. The commands can be substituted with however you would transfer the PDF from your PC to your phone.
The barcode should be immediately scannable but it may not have effect until the next poor sucker installs Delhaize’s shitty proprietary closed-source app and registers the card in their name. Thereafter you should get the instant discounts on what you buy but obviously any points accumulation will go to your surrogate. Sure, you could probably exploit the points too but don’t be evil. Your surrogate is your friend. Fair enough that they get the points credit.
Mods
The barcode will not have the exact same cosmetic style as the card (the leading and checksum digits are visually offset). If you care about this, you could:
- Add the
-n option to the barcode command to omit the digits, then use ImageMagick or GIMP to insert the digits below the barcode; or
- Use LaTeX to generate the barcode. I’m not sure how to generate a “UPC A” barcode in LaTeX but you likely have complete control over the format
You could pass the -t option to the barcode command to print many copies on a page of sticky labels to give to give to family/friends/colleagues. Those stickers could be put over top of barcodes on other cards which no one activates.
Unworkable shortcut
Theoretically you could simply scan the barcode and use the same barcode app to generate a UPC-A barcode. My app detects the barcode as UPC_A and correctly decodes it, but when the app tries to re-encode the digits into UPC-A it produces a 2D barcode (like a QR). I doubt that works because the cashier’s scanner is likely only for 1D linear codes.
Perhaps other apps can do this correctly.
Notes
The Delhaize barcodes do not seem to start with a “2”, which seems questionable because a 2 normally indicates internal use. So does Delhaize run the risk that their loyalty cards clash with UPCs of actual products? Maybe they actually legitimately bought a range of product codes for memberships but seems like a waste of money.
UPDATE - Why I’ve decided not to do this
It has come to my attention that loyalty customers who run the app have access to their own shopping history. At the same time, couples often share an account and see each others purchases. So consider this scenario:
Bob and Alice are a non-drinking couple, but Bob had a drinking problem historically. Suppose he is on the wagon. If suragate Mallory buys alcohol, Alice will think that Bob is sneaking alchohol which would lead to confusion and misery. Mallory could avoid buying things like alcohol and tobacco, but there is also the problem that Alice or Bob could be using the receipts for accounting and bookkeeping.
Since there are unpredictable problems with this, I think this anti-surveillance advertising move should not be used.
I appreciate the insight. My other speculation was that it was an anti-spam tactic.
In Belgium residents can post a sign/sticker saying /no pub/ and by law it must be complied with, but there is no enforcement and not much compliance. Unlike Switzerland, who charges people to opt-out of ads but then diligently fines violators.