At least around the holidays you should just increase your prices a bit
to cover the extra cost of UPS/fedex shipping. Sure, you might get less
sales, but it's better than using a service that'll likely have problems
and end up causing the buyer grie...
If I bought something from someone who chose to use USPS instead of
UPS/fedex to ship it to me (and this always irks me when someone uses
USPS to ship something to me) and I haven't received it in weeks I would
file for a refund too. It's the seller'...