> Visa's market research suggests a significant increase in Visa usage and Visa brand value among consumers aware of their Olympic sponsorship.

Couldn't this be that heavy-Visa users notice the company's sponsorship and usage more generally? This doesn't really prove that Olympics sponsorship increases usage.

> The same report found Visa’s brand equity was higher among consumers who were aware of Visa’s sponsorship.

Again, couldn't it just be that the kinds of people who notice that Visa sponsors things are the kinds of people who already like Visa? This doesn't establish that sponsoring the Olympics helps Visa.