Typically, the most basic objective is to generate enough leads that, when converted into sales and long-term customers (Relationship Marketing), results in more profit than direct costs….in other words, a positive return on investment. Note however that it can take some time for the full benefit of a direct email campaign to become apparent. While responses may come in within the first two to four weeks of the initial mailing, others may take longer. Or the response may come in without a clear connection to your mailing, in the form of a referral to a spouse or friend. Using a promotional code on your email piece can improve your ability to track how well the campaign is performing.