This is not necessarily true...
I understand where you are coming from, but advertising "two different things" is still market advertising none the less. It shouldn't matter whether one is a link to your shop, or the next one advertising "Buying Membership Pm me". They're the same thing.
Also, we do keep track of times. The shoutbox does not provide a time of shout feature, therefore we must keep our own record of things; and we do provide this information to staff members upon every ban. We aren't just assuming, that would make the whole system flawed. :P
Anyways, I understand you're frustrated and I agree with some of your points. Best of luck, Blue! ^_^