According to Ev Williams, Founder of Twitter:
“Here’s the formula if you want to build a billion-dollar internet company,” he said. “Take a human desire, preferably one that has been around for a really long time…Identify that desire and use modern technology to take out steps.”
His recent example is Uber. “How old is the desire of getting from here to there?” he said. “How hard was it really to do? They took out some steps in that process…They formed a connection between you and the driver.” (via Wired)