Portland, OR
I have found it is best to just charge a pinch more and ship everything priority. They get it way faster and safer. I'd rather eat a bit more cost and have the cust pay a couple dollars more and get the package way faster. So basically the small increase for priority is split. It is of course a bummer when people only need a few bulbs and the order itself is $10 and the shipping is 6-8$, but I had too many issues with the cheap options. They were slow, abused and lost a lot more often.
People love the cheap and slow option until that includes "cheap, slow and lost" and no insurance is on it.
I have amazon prime personally and still pay the the extra few dollars+ to get it in one day all the time.
I mostly only have lost package issues when shipping to Canada, but that is because it goes the "cheapest" first class option since priority is nearly double on international.
USPS tracking is so awful though compared to UPS/FedEx 
Sometimes goes a bit without updates that are a frustration for us and customers of course.
Quoted from Bigbossfan:I don't know how much of your business is generated in Canada......but I know UPS or anything other than USPS is a killer for us!
This is why I still USPS. At shows and working with the Canadian customers they all have this same feedback. I hear something that UPS.FEDex rails you guys for taxes or something like that awful
