How Much Should You Spend to Acquire New Buyers?

Some catalogers say they want to base the cost to acquire a new buyer on the expected lifetime value. This is a reasonable approach, but most prefer to take a shorter-term view. While it’s unrealistic to expect to prospect in total (on a cumulative basis) at or above the break-even point, it is reasonable to try to pay back that investment in one year. How much can you afford to spend for a new buyer, assuming a one-year payback?