Targeted advertising

It was about two months ago when I first noticed an advertisement on some random web page that contained an image of a vintage Jaguar XJS. It was not exactly the same model as I have, but very close. Judging form the bumpers and trims it also seems to be a HE (High Efficiency), as the second series was called. But the wheels are different. The advertisement was for an online auction platform for cars. I immediately assumed it must me a targeted ad. I was impressed that they must be able to dynamically select the type of car they want to show. How many polished pictures would they have readily prepared?

Last week, the same advertisement appeared in the printed edition of 20min, the largest free commuter newspaper in Switzerland. Now this could not be targeted any more…



After a long pause, I just started attending a MOOC again. It’s on Coursera, from Princeton and it’s about BitCoin. In one of the first lectures the teacher goes through some simple hypothetical digital coin concepts. I don’t know if the lectures are publicly available piecewise, but as a whole they are at youtube. Jump to minute 50 for scroogecoin.

Name property problem
GoofyCoin signed receipts double spend
ScroogeCoin centralized blocks corruption
BitCoin fully decentralized solved


ScroogeCoin reminds me a lot of the blockchain projects a lot of big financial institutions announced over the last few months. They talk about permissioned blockchains. That sounds like exclusive access and centralized control. BitCoins inclusiveness is one of the important characteristics, and I hope enough people recognise it as such.


When VISA doesn't work

I used to order stuff from dealextreme on a regular basis over the last few years. Like many other customers I asked them to accept BitCoin payments. But that didn’t happen so far. So we are left with the payment options from the last century for the time being. It used to work acceptably so far … until about a month ago, when my payments suddenly started being declined. The same VISA debit card used to work with dx before, and it remains working with other merchants. Of course I checked the balance. I dont keep much more on that account than I expect to need in the short term. But $250 should suffice for a $200 order, so the problem has to be somewhere else.

Dx states it on their page unmistakeably that all payment problems are not their fault, and that people should consult with their issuing bank. So I contacted them first. They couldn’t find anything about the declines in their logs:

There are no transaction attempts on your card for the merchant, not on July 27th or after.
In those days I can see transactions at merchants X, Y, Z - which all
look like they are still pending and waiting to be completed
(a few months ago we updated our payment processing system to
adhere to settlement standards).

For some reason it looks like the payment authorization never reached Us..
When a payment takes place (when you use your card), what happens
first is that the merchant informs Visa, Visa then informs our card
issuer, and the card issuer informs us about a new transaction on
your card. We then hold the corresponding funds from your wallet.
Then a few days later, the merchant settles the transaction
(ie. broadcasts to the network whether the transaction was
completed or not), and we use that information to complete your
transaction. What is strange is that the authorization for your
purchase at either never reached Us, or never
left the merchant's system.

Because you've been able to use your card in the past few days,
I'll dare to say that there's nothing wrong with your card - rather
it seems like a glitch with this particular merchant.

So I asked the card processing intermediary. They had no means of secure communication. I found it hard to believe that a financial institution can only communicate with their customers over unencrypted cleartext eMail.  However, I got similar results:

Please be informed that we could not find any decline on your card at our end,
which means it could be an issue with merchant end.
We request you to check with the merchant regarding this.

Finally I went back to dx and got this answer:

sorry for that.
but our related staff told us your bank reject the payment.
that is not our problem.

From all I learned so far, it seems like VISA is the problem here. But I don’t have a contact or a direct relationship with VISA. It is routed over shady ways through an unknown number of intermediaries. The best explanation that I can come up with is that the transactions triggered some kind of fraud alert and were thus blocked. Is that how they deal with the lack of a secure system? They just randomly block transactions! With no way of recurse, such false positives are really annoying for their customers.

So what do I learn from this? When there are too many intermediaries in the loop, there are more chances for errors and errors are harder to find, let alone fix. With BitCoin, there are no middlemen and a lot less things that could go wrong. I have been using BitCoin whenever possible for the last four years. Nothing alike ever happened with BitCoin, in fact this would be unimaginable with a peer to peer blockchain system. I’m really looking forward to leave all those ancient¬† payment methods behind…

Ironically, I read this story the same day I got the last answer from dx.