Reuse of successful concepts
Companies and their people often take a concept that has proven to work before and apply it to another use. Concepts created online get offline and vice versa. When the film "Harry Potter" became successful, many new episodes appeared, which multiplied its effect. Everyone was so excited, that soon there was demand for Harry Potter books too. Suddenly, Harry Potter was everywhere. There is nothing wrong with taking a concept and applying it repeatedly. The problem is that all good things get overused.
"Avatar" was another highly successful film. Its creators said that their profits were so high partially because of the 3D version in addition to the regular one. Many people wanted to experience the difference, so they took the special glasses. Then, the game Avatar for iPhone appeared, creating a psychological effect, so the people that watched the films felt that they need the game too. Of course, they were ready to pay for their crush.
Iskren Lozanov, a bulgarian fashion designer, created a piece for an underwear contest, which was inspired by a work of Picasso. The crew of Beyonce took the concept and applied it in her song "Video phone". Lozanov said that everything was copied six months after the work originated, so he said that he'll seek his rights. Repeated, copied use of other people's work leads to lawsuits.
Apple decided to reuse the concept of the highly successful iPhone in their iPad—a product with similar capabilities, but a different form factor. Pad-like devices already existed before, but they never got popular as they weren't comfortable to use over longer periods of time and they didn't have touch screens. But even on touch-screen devices, the input of longer texts can be slow. The feedback on typing is unconvincing, because it has only visual nature, compared to a real keyboard, which lets us feel the keys we press. One of the reasons why the iPad won't support the successful Flash plug-in is, because it is computationally intensive and quickly drains the battery. Comparing the iPad to other devices like the Kindle isn't appropriate—Apple can't use black-and-white screen technology for web browsing. For long reading and good readability, the Amazon's device will remain a better choice. When new devices appear initially, they often have problems: low battery life, high temperature, display problems, easy-to-scratch surface and others. In such cases, the majority of people are leapfrogging.