The second one is definitely okay - it's providing info for a service that doesn't compete with HuskerBoard, and is information that the members would want.
The first one is a closer call. Definitely spam, but...the shirts on that site are not the kind of thing we'd tend to sell anyway (well, the "add 0.1" we might). So, I don't see that site as real "competition". Having said that, we might want to wait for ETR to enter the discussion on this. I'd be inclined to let it go, but I'd like to hear what Eric has to say.