Exclusively for Prime members, Amazon offers this Dog Food and Treats Sample Box bundled with an $11.99 Amazon Credit for $11.99 with free shipping. (The credit must be used towards purchases of similar dog food and treats.) Assuming you'll use the credit, that makes the sample box essentially free, and is tied with our March mention. Each box contains six or more samples from brands like Blue, Wellness, Hill's, and Canidae.

Note: It's expected to ship in five to seven days.