The "KHAN ACADEMY" is a "fast-paced nonprofit startup that is backed by the Bill and Melinda Gates Foundation, Google and other leading philanthropists. Its mission is to provide a free, world-class education for anyone, anywhere".

Khan Academy already provides education to millions of students. Its website features thousands of educational resources stored on Youtube. The academy could be "the world's first free virtual school -- with content across many subjects, extensive math practice problems, and personalized learning software, for learners with a wide variety of learning objectives." The website counts over 6000 micro lectures.
"What Sal Khan is promoting is more than a library of videos, which at this point holds lessons on subjects of math, science, economics, computer science and the humanities; Sal is promoting a pedagogy where the learner is self-directed, in the center of the learning paradigm, and teachers, act as mentors and guides rather than directors of learning (The One World School House: Education Reimagined, p 242).
Sal also believes that students can be inherently motivated when the conditions of learning are right. He has a vision for classrooms of the future, for an education system that is almost a utopian one, featuring the ‘ideal’ where students learn and grow at their own pace, at no cost, anywhere in the world." (D.Morrison 2013)
How is it innovative?
Khan's vision of education is the main innovation. His initiative, of filming video tutorials to help his niece with basic Algebra and sharing them with her on Youtube, was only a major boost to get known and start spreading his ideas on education.
The real innovation consists of using technology as a main tool to create a learner-centred and tailored learning system. The idea is that "Students of all ages combined in class, spending only one or two hours on lessons, and spending the rest of the school day with hands-on learning and projects. Standardized tests would be few, and transcripts a thing of the past."
Why is it so successful?
Khan Academy is a total free online platform. Thanks to this business model based on 100% free education, millions of people worldwide can afford taking "classes" on almost any field. One of the most famous pupils of Khan academy is Bill Gates. Gates said "Khan, this teacher to the world is giving us a glimpse of the future of education".
REFERENCES
Salman Khan on Charlie Rose 2013. Accessed October 10, 2014. <https://www.khanacademy.org/talks-and-interviews/key-media-pieces/v/charlie-rose-2013>
Khan Academy official website, "A free world-class education for anyone anywhere". <https://www.khanacademy.org/about>
"Khan Academy Fact pack" (PDF). Khan Academy. June 1, 2014. Retrieved 2014-06-15 <https://dl.dropboxusercontent.com/u/33330500/KAPressFactPack.pdf>
Salman Khan, "The One World School House: Education Reimagined", October, 2, 2012.
Debbie Morrison, "Can We Transform Education with Sal Khan’s One World Schoolhouse?" <http://onlinelearninginsights.wordpress.com/2013/02/10/can-we-transform-education-with-sal-khans-one-world-schoolhouse/>