I set up my listings in such a way that the user never selects the actual service I use.
There are two really important reasons why.
I learned from a few years working for a mid-sized internet retailer that customers that pay up for faster than normal shipping are big time problems. They have huge rates of charge-backs and are much more likely to be using stolen credit cards or accounts. The legitimate customers tend to need the item faster than it is going to legitimately get there given the fact that they usually order after hours or on the weekend. They will order next day shipping at 5:30 PM on saturday and expect it to be there for their party sunday afternoon. When in reality the shipper won't even get the thing until monday evening given when they ordered.
Second reason, I want to be able to select the best possible price on my end every single time. There can be huge differences between rates for the same order going to the same place while realistically there is going to be very little difference in how long it gets there and I don't really want time sensitive customers in the first place, which is why I list 3 day handling time despite shipping next day.
