Here's some more interesting info.
http://www.corporate.visa.com/mc/press/press156.html
What is said there is that visa brand is chosen by 50% (maximum) of respondents. In other words with the exception of USA market , where I guess numbers probably are the same, Visa is being used in 50% of credit card purchases, and that's according to VISA
.
When in online world all of us know that the actual number is 70%.
And that is the answer to the evergoing question "Why?" and all cospiracy theories - at least 20% difference that's why.