Storage is the total sum of the data used by your store. This includes:
Through the Analytics tab in Bigcommerce, select Storage & Transfer.
This report will show you the the total amount of storage you have used, as well as a breakdown of what it is being used for.
You can move your mouse across the graph to get a day-by-day breakdown. If you are currently over your plan's limit, you will see a link to upgrade.
While deleting information from your store is an effective way to decrease your used storage, it is also a big step and should be carefully considered before proceeding. We recommend that before you do this, you have a look at our article covering how to back up your information.
This is another area that can quickly grow if not closely watched. The simplest way to eliminate it is to host your email with a third-party service such as Google Apps, Yahoo, or GoDaddy by re-pointing your MX records to that service.
If you do use Bigcommerce's mail servers, another option would be to switch from IMAP to POP3.
The primary difference between these two mail protocols is how read messages are handled. While IMAP will maintain a copy of each message on the server until you choose to delete it, POP3 stores the message on your local machine and erases the server's copy. While this is an effective way to keep your storage utilization low, it has the drawback of making the message available only on the machine that retrieved it, which can be a problem for clients who use more than one device to check their email.
The images portion of your storage contains the large copy of all of your product images that are shown in zoom view. The best way to manage these is to ensure that you optimize your product images prior to loading them into Bigcommerce (This is actually a good practice for any image you place on the web. No one likes long load times).
If you have access to image editing software such as Adobe Photoshop, you will have built in optimization tools that you can use when saving your files. If you don't take a look at some of the free online tools available to you, such as Kraken.
This is where you're going to see things like custom template modifications, information you've upladed for your customers such as PDFs, downloadable demo videos, as well as information your customer's have uploaded for you via a configurable field.
The easiest place to start is the /product_images/import/ folder. This is where you initally upload images to when doing a CSV import of your products. From here, the images are resized if necessary, and then placed into folders where they are accessible from your storefront. Eliminating this directory after you've ensured the products are succesfully loaded is a great place to eliminate some unnecessary megabytes.
Another area to look at if you use configurable fields to allow your customers to upload files for you, is the /product_images/configured_products_tmp and /product_images/configured_products directories. Going through here and ensuring that you're not holding on to files for orders that were fulfilled long ago is a good practice, especially for stores that take in large files such as high resolution graphics for printing.