Clayton M. Christensen said this quote
“ To measure market needs, I would watch carefully what customers do, not simply listen to what they say. Watching how customers actually use a product provides much more reliable information than can be gleaned from a verbal interview or a focus group. Thus, observations indicate that auto users today require a minimum cruising range (that is, the distance that can be driven without refueling) of about 125 to 150 miles; most electric vehicles only offer a minimum cruising range of 50 to 80 miles. Similarly, drivers seem to require cars that accelerate from 0 to 60 miles per hour in less than 10 seconds (necessary primarily to merge safely into highspeed traffic from freeway entrance ramps); most electric vehicles take nearly 20 seconds to get there. And, finally, buyers in the mainstream market demand a wide array of options, but it would be impossible for electric vehicle manufacturers to offer a similar variety within the small initial unit volumes that will characterize that business. According to almost any definition of functionality used for the vertical axis of our proposed chart, the electric vehicle will be deficient compared to a gasolinepowered car.This information is not sufficient to characterize electric vehicles as disruptive, however. They will only be disruptive if we find that they are also on a trajectory of improvement that might someday make them competitive in parts of the mainstream market. The trajectories of performance improvement demanded in the market—whether measured in terms of required acceleration, cruising range, or top cruising speed—are relatively flat. This is because traffic laws impose a limit on the usefulness of ever-more-powerful cars, and demographic, economic, and geographic considerations limit the increase in commuting miles for the average driver to less than 1 percent per year. At the same time, the performance of electric vehicles is improving at a faster rate—between 2 and 4 percent per year—suggesting that sustaining technological advances might indeed carry electric vehicles from their position today, where they cannot compete in mainstream markets, to a position in the future where they might. ”