Samsung has not yet revealed official pre-order numbers for the Galaxy S6 and the Galaxy S6 edge though it is believed that the company's carrier and retail partners have placed orders for up to 20 million units of both flagships combined. Recent reports also suggest that Samsung has had to triple the original production volume of the Galaxy S6 edge due to unprecedented demand from its partners. Clearly the demand is high or else Samsung wouldn't have to charter Boeing 747 planes, fill them up with pallets stacked with the Galaxy S6 models and fly them over to the United States.
This is one move that Apple has made many times before, sending planes filled with the latest devices to ensure that there's ample stock available at carrier and retailer partners on launch day. Given the fact that early reviews for both devices have been very promising it wouldn't surprise anyone if the Galaxy S6 and the Galaxy S6 edge end up doing very well in the market. Samsung may presumably take similar steps for other lucrative markets as well that are part of the 20 countries where the Galaxy S6 and the Galaxy S6 edge will be released first on April 10.