Why buy the same brand twice?

We can learn a lot from analysis of just two purchases--namely that most people are not loyal, but instead switch their purchases from one brand to another. This is a regular pattern for all brands, but the loyalty level for bigger brands is greater than for smaller ones. This illustrates the double jeopardy law. The surprising finding is that the law can be demonstrated with the use of small sets of survey data, making the two purchase technique valuable to smaller, less data-rich companies.