The real sharing economy is not about renting out your apartment on Airbnb or offering your services as a taxi driver on Uber. These are both good services but it would be completely wrong to label them as pioneers of the sharing economy.
The true pioneers would be the technological sharing culture with projects like Linux, Wikipedia, Github and Open Street map. The communities that developed the Internet in the 90s and the important work by the free software movement in the 80s built the foundation for one of the largest paradigme shifts in history. The Creative Commons movement that has grown strong over the last 10 years has also played an important role in creating a strong sharing economy.
If one were to look for companies that can be called pioneers in the sharing economy it would have to be Amazon, Google and Redhat.
People like Richard Stallman, Tim Berners-Lee, Lawrence Lessig and Håkon W. Lie are pioneers of the sharing economy trough significant contributions that deserve to be mentioned.