About 10 years ago, I dated a woman who worked at a distillery, and they were looking for some software to automate the labeling and shipping process for their bottle and label samples. FedEx just released their API, so, I wrote them a little web based program that generated the label, and then automatically identified which packages were delivered outside of the delivery window so that they could be submitted for refund.

While FedEx had no problem refunding the shipping for the packages that were delivered outside of the window, they raised the distillery's rates dramatically (over 100%) over the next few months. At the time, UPS nor USPS would accept packages from a distillery (regardless of if they were shipping spirits or not), so, I turned off the functionality that sent the 'out of window' reports, and a few months later, the distillery's rates went back down to normal.

Would I use this today? Not at all -- FedEx is really on top of areas where they're going to be delivering late and if you have a package or packages going to that area, they're preemptively sending you "Service Alerts" letting you know that they're using the weather or other clauses from their terms of service to not honor the guarantee. I haven't shipped UPS in years due to them not wanting to pay on a warranty claim, but my guess is that UPS is probably also doing the similar type of things to their customers as well.