You're missing the point. If I post the same ad directly on PadMapper (let's say), how does one know if PadMapper scraped it from Craigslist or I cross posted

You're missing the point. If I post the same ad directly on PadMapper (let's say), how does one know if PadMapper scraped it from Craigslist or I cross posted it? The way it reads, and the only way I can imagine it could be enforced, is that you are granting Craigslist the exclusive right to advertise that item or at the very least the exact text you used to advertise that item. Either way, it's ridiculously heavy handed.