Whether or not to use first class or bulk rate (third class) postage is a perennial question that never seems to go away. In one sense, that's the way it should be, because the factors that favor first or third class tend to change over time. One could argue, for example, that as the volume of bulk mail increases, people's patience with it decreases, and this diminishes its effectiveness.

Our experience is that, generally speaking (and this is by no means a blanket rule), bulk rate is more cost-effective. First class will nearly always generate a higher response (and I could expound on any number of reasons why this is so), but in most tests we conduct, the increased response is not enough to offset the increase in cost. In other words, third class results in a lower cost per lead.

Here are three scenarios in which first class is generally worth the money:

1. Campaigns targeting the federal government.
2. Campaigns targeting Fortune 500 companies and/or high-level (CEO-type) executives.
3. When lead time is an issue (ex: a seminar invitation).