Scott Berkun is the author of "The Myths of Innovation". One of the most interesting myths that he debunks is also one of the most widespread. The myth is: people love new ideas.

The reality is the exact opposite. People don't like new ideas. An innovative product rarely succeeds because it's a better solution. If it was, we'd all use the metric system, have twheels on our car, and use robertson screws.

So why do innovations succeed? Berkun outlines the following 5 key factors:

• Relative Advantage: You can predict how successful an innovation will be by looking at the perceived value of the innovation compared to the current solution. Is it easier to use, better to look at, more reliable, more effective, etc?
• Compatibility: How hard is it to start using? If the cost of switching to the solution is high, then people won't transition. The transition has to be less expensive than the perceived value of the advantage you gain.
• Complexity: How big is the learning curve? If it requires people to re-learn old habits then you have serious impediments to adoption.
• Trial-ability: Can people take it for test drive, or give it a trial run? The easiest way to overcome someone's objections is to let them try it.
• Observability:How visible are the results of innovation? The more visible the benefit, the faster the idea spreads.

In short, innovations that are easy to adopt and highly visible spread faster than those that aren't.

Superficial innovations (like fashion trends) spread quickly because they are highly visible and the cost to transition to them is low—especially when compared to the perceived benefit of increased social status. However, something like transitioning to the metric system, which requires an entire country to change their measuring cups and throw out their old cookbooks, rarely happens on it's own.