Over the past decade, companies have begun using online ordering capabilities to develop a powerful marketing tool—“mass customization” systems that let customers design their own products. For example, Nike, Lego, Threadless, Porsche, and Ford all give consumers the ability to choose colors and other options. Research shows that consumers value self-created products more than ready-made ones. (As a result, some companies charge more for do-it-yourself, or DIY, designs.) Companies have recently started encouraging consumers to use social media to “share” prototypes of their self-designed products with friends before finalizing their choices.

A version of this article appeared in the July–August 2013 issue of Harvard Business Review.