This idea would have been more intriguing 5-10 years ago when people were more used to plugging stuff in and out and cloud based services weren't so ubiquitous. It appears that they took a long time to develop the USB part and missed the boat on that. Even the card's NFC chip, which seems to have been an afterthought in development for this product, is a more compelling feature that its main selling point.
I simply don't see this product's utility as a business card. If I want to get in touch with someone after receiving their business card, the only information I need from that business card is their email address; I'm not going to plug in a USB device just to get that email address. If I want to save all the info on the card, Evernote is already better and simpler at solving that problem.
The only people I can see this possibly being useful to are photographers for sharing their portfolio, but, again, it would have been a lot more useful for that purpose 5-10 years ago.