Are certificates that save buyers money while they purchase specified products.

the answer is: guns or butter

hope i

-lavira : )

1) the stages a new product goes through from beginning to end, i.e., the stages that a product passes through from introduction through growth, maturity, and decline. 2) the time from initial research and development to the time at which sales and support of the product to customers are withdrawn. 3) the period of time during which a product can be produced and marketed profitably.

                                          hope it