One of my favorite ways to save money

I try to take advantage of Amazon's monthly grocery specials.
Every month, Amazon features a number of instant rebates when you purchase a certain amount of a type of product from them. For example: this month they are offering an instant $15 rebate if you place an order of $39 or more worth of select Kellogg's products. So, you get $39 worth of Kellogg's products for $24. Most orders are above the $20 threshold for free shipping.
I like their system. They give you a code, a list of eligible products and a target dollar amount. The challenge is to make an order that gets as close to the dollar amount as possible.
I've made quite a doomsday pantry of non-perishable goods and supplies through Amazon.
It's a great way to save a good chunk of money.
It's also a way that I've learned about a number of really good products.