Virtually Everybody Should “Virtually Mark”

We’ve all seen them. Those old-timey looking patent stamps, branded on clever products.
Why do companies do this? Because a patent number, stamped in bold letters, looks impressive? Does touting patent coverage as a badge of honor (or, at least, unique utility or design), help to sell the product?
Yes, and Yes! Patent marking increases the perceived quality and value proposition of a product tremendously, and Products that are marked as patented sell more than unpatented products.
But these reasons, which we all naturally get, are not even the main reason companies MUST mark their patented goods.