So, what is Amazon FBA and why is it used more than FBM? Well, FBA is better for high volume, higher margin products where sellers don’t want to handle storing and shipping products. FBM is better for smaller scale, small margin products or one-off products where the seller doesn’t mind storing and shipping products. If you like having more control over your inventory then FBM is for you, however, if you like the idea of Amazon storing and dealing with returns, then FBA is the way to go.