Rule of 300(redirected from Rule of 300's)
Rule of 300
In marketing, a general rule stating that one should send out enough direct mail to receive at least 300 responses. The rule of 300 involves establishing an expected response rate. For example, if the expected response rate is 10%, the marketer should send 3,000 pieces of mail. The rule of 300 ensures a fairly representative response. In this sense, the rule of 300 is rather like polling.