Driven by a new wave social applications like Facebook and Twitter, social networking took only three to four years to reach a mass audience, says Kurzweil. "Innovation is happening faster and faster, and what is driving that is the exponential growth of information technology, which is extraordinarily predictable and uniform," says Kurzweil. Of course, timing is key in exponential progression. "Why didn't social networks take off until about before four years ago?" asked Kurzweil. "Is it because [Facebook Co-Founder Chairman and CEO] Mark Zuckerberg or his equivalent didn't come around? No, it just was not cost effective."