As of 2015, Ninja replacement cups can be purchased from Bed Bath & Beyond, Kmart and Ebay. Most of these units come complete with convenient to-go lids.
Bed Bath & Beyond sells single serve cups with lids in a set of two. With a capacity of 16 ounces, these cups are designed to be used with the Ninja BL660 Professional Blender & Single Serve. These cups are constructed with BPA free plastic. Both cups are dishwasher safe. Some users report success using these replacement cups even when using a Ninja blender with a different model number.
Kmart also sells replacement cups designed for the Ninja BL660 in a set of two. For those participating in the Kmart rewards program, purchasing this product earns the user a total of 180 points. Ordering the product online and picking it up in-store is completely free. Home shipping is available at an additional cost.
A number of Ninja replacement cups are available for purchase on Ebay. Since many of these items are sold by individuals, the quantity of product available at any given time varies. However, Ebay offers more variety in terms of make and model availability. This means that individuals with older Ninja units may find the appropriate cup more easily.