What does "Ships by Itself" do on the product Information Tab?
As you enter products into your store, you'll eventually get to the part of the Information Tab where you can specify the product's weight and dimensions.
Along to the right of this area, you'll see a text box labeled "Ships by Itself" which can have drastic effects on the way your store calculates shipping costs.
When checked, this setting will tell the store that - when the item is ordered - to consider this item as shipping separately from the rest of the order. Regardless of any other items that are purchased on the order at the same time, items marked with "Ships by Itself" will be factored as their own separate box when the real time shipping rates are calculated.
It is intended for situations where the item needs to be sent in a unique container from the rest of the order. Perhaps it requires special packaging or maybe the item itself has a weird shape that won't fit into a regular box.
A good analogy to think about for the setting is to imagine a store that sells DVD movies.
Whether the shopper purchases 1 or 5 DVDs in one order, it's a safe bet that they'll all fit into the same generic, rectangular box like this:
Therefore, the DVD products aren't marked as ships by itself because they can all fit together in the same box for the most part.
However, the store also sells collectible movie posters. And not just any old posters either... These are really nice movie posters. We're talking "printed on both sides" and "intended for the true collector" type movie posters. Seriously, you don't want to fold these things and cram them into a rectagular box with the rest of the DVDs. No no no... These posters need to be carefully rolled and placed inside their own cylindrical container like this one:
In this situation, the merchant would mark the movie poster products as "Ships by Itself"
This way, when the shipping calculation call is made to the shipping carrier, the rate that is returned to the order will reflect that the shipping will be for one box full of DVDs and one separate container for the poster.