Selling data is a one-time occurrence This is not necessarily true. Depending on the deal you make with address brokers you more often than not hire specific a

Selling data is a one-time occurrence This is not necessarily true. Depending on the deal you make with address brokers you more often than not hire specific addresses for one time use. You are not allowed to reuse them for multiple mailings without paying additional fees. In order to enforce this address brokers seed the data with control addresses. Carefully curated address lists (say, something like C level managers with an income > 500K $, for example) are expensive, even for one time use. If an address broker outright sells addresses those are usually of very low quality.