Otto Frederick Rohwedder invented a prototype for a bread slicer in 1912, and it was nearly a failure.
Until 1928, he wasn’t able to sell a single loaf of sliced bread. Like most inventors, he focused more on the technology rather than popularizing the idea behind it. He drafted elaborate drawings of bread-slicing machines and filed patents. However, nobody cared for sliced bread. The idea didn’t catch on.
Finally, in 1930 a US company named Wonder sold bread pre-sliced nationwide. This campaign was responsible for making slices the most obvious form in which bread is sold all over the world. Yet, this idea wasn’t obvious until the right marketing campaign made it so. In fact, it almost died out.
The best means to strengthen an idea is to spread it rather than protect it.
Source: History of Sliced Bread