I've shipped 99% of my packages with USPS for the past 7 years since it is much more cost-effective than UPS and Fedex, since I'm shipping lightweight apparel in polymailers.
This week alone, I've received 5 emails from customers who've had their packages marked as delivered but claim they never received it. Usually, I'll get emails like this once every 1-2 weeks and after a couple days it'll show up but this hasn't happened for any of these. I;ve had a few instances where USPS would deliver to the wrong house. Last week I also had a few customers who's packages were 'Out For Delivery', and then the tracking never updated after that for a week or more. I ended up refunding these customers only for the items to be delivered to them a week later. Mind you, these were Priority shipments!
I'm really considering using UPS moving forward and dealing with the extra costs just so I do not have to deal with opening USPS cases, filing missing claims, customer support, etc. it is pretty unbearable now. Those of you who use UPS/Fedex for the sake of reliability over cost, how often do you experience issues like this? Do you ever experience any issues?