In the screenshot, the checkbox is actually checked off. Was that the default setting? If so, I could see that being off-putting to users -- whenever I see that, I assume they're trying to trick me into opting in for something.
That is, they set off alarms not just that they might be subscribed to some email list, but that a "free trial subscription" (that auto-renews to a paid subscription) is being added to the order.
I'm touchy about my inbox. I let DailyBurn email me for as long as I had a paid account there, and I still let OKCupid email me, years later. But they both had to earn my trust with a combination of a slow start and relevant emails. Pretty much everyone else annoyed me immediately.