What is the most important aspect of successful merchandising?

The most important aspect of successful merchandising is 'Ability to Prioritize'. Hundreds of daily tasks are there for a merchandiser. If a merchandiser can prioritize the jobs for daily basis, that will elevate & accelerate the total load.Ultimately it will make the job effective. 

Visibility of the orders

A merchandiser like a factory for a buyer also a merchandiser like a buyer for this supplier.

Merchandiser must have good knowledge about the product, production line and running trend.

Also, he / She must update about the current market price.