So around this time of year I always run PPC ads to try and cash in on the Xmas rush. But there's something I've noticed - very often, the product I'm promoting will run out of stock, and I'll end up sending traffic even though there's no chance of conversions. Does anyone have any advice on how I can limit this? Obviously I try to check my stats as much as possible, and put a stop to any campaigns that show huge traffic spikes without proportional increase in conversions, but is there a more efficient way that won't require constantly having to monitor data all day? That can get tedious if you're running lots of campaigns. For instance, does anyone have a script that connects to Amazon (or other retailers) API and automatically pauses campaigns on Adwords, Facebook etc when stock levels reach a certain point?