I suppose it depends on the demographic, if the olympics is mainly attended by relatively affluent people with multiple credit cards. I know plenty of people who don't even have a credit card beyond a bank issued Maestro debit card.

Even if the percentage overlap approaches 90%, I don't think it's a smart move. It's very anti-customer and will cause a decent percentage of people a great deal of angst and a much larger percentage of people will be quite disappointed. And don't forget that high-spending corporate travelers use Amex almost exclusively.

The problem with a payment provider striking an exclusive deal like this is that it creates very real problems for people unlike, say, and exclusive beer deal. And it creates a great deal of negative feelings towards both Visa and the Olympics. I'm sure Visa is able to show that it is a good deal for them. But I suspect it is just as easy to show the opposite. Not smart at all.

I agree, though I would think the ratio is the opposite. The thing is, having multiple cards might be a sign of wealth, but it's also a consequence of local culture. In some countries, everyone has a gazillion of cards. In some countries, having two cards is sort of an exception. In some countries, half the shops usually don't take VISA (Belgium is like that iirc, but I might be mistaken).

So, by taking a decision like that, you're alienating quite a few people, based on non-relevant criteria (not wealth related ones).

Well, anyone who was British and bought their tickets through the official UK process for buying Olympic tickets had to use Visa to pay for them anyway. I think lot of people bought their tickets through travel agents, though.