i think every company is suitable to different sellers depending on WHAT they sell. small items would be best suited for cp, as they're the cheapest...larger and heavier items for fedex etc...
i sell all kinds, so i mostly use cp, but sometimes fedex or ups all depending on size, weight and value...
if you sell only one type of product, then you should figure out based on size and value etc...which company best suits you. i have recently lost lots of respect for fedex...over a month ago, i sent two packages with them...one they lost, the other they sent back completely damaged, and i STILL haven't heard one thing from them. very discouraging.
Kat