Businesses are always on the lookout for information they can use to connect with their customers and market their products more effectively. Sometimes the information you need has been right in front of you the whole time, sitting in your customer database—if you know what to do with it.

Once upon a time, you could place marketing calls to anyone you wanted. They might get mad that you interrupted their dinner, yell, and hang up on you, but it was all perfectly fine and legal. Then, in 2003, the Do Not Call Implementation Act became law.

The year was 1991. Cellphones were still rare, a novelty to most people.