Castmark gives podcasters one durable redirect link per sponsor. Paste it into your show notes once, in every episode. When a sponsor changes their destination URL, update it in Castmark and every episode, past and future, points to the new link instantly. No more re-editing old show notes. Every click is logged by device, referrer, and time, then rolled up per sponsor, per campaign, and per episode, so you can tell a sponsor exactly which episodes drove clicks instead of guessing.