Their quality is actually really shoddy as well, and the free cards all say "print at VistaPrint" on the back of them. Not to mention the fact that they go to all lengths with retention emails after you place a single order (without having the option to opt-out) to keep people ordering more. They also charge a ton of hidden fees.
In short: If you want your business card to be a serious reflection of your business, DON'T use VistaPrint.
Free cards do say that on the back, but they're free. What would you expect? They aren't meant for serious business use, for that you should pay like you would anywhere else (but less).
I haven't had any trouble with spam from them ever. And even if I did, it would be 2 clicks to just block their emails in the future.
Perhaps your roommate doesn't like his job and is not the best person to ask?