Most of the times innovation is just about new thoughts / new process of existing business model. Vacation Rentals were a successful business model mostly famous for long stays in US and Europe, it lacked larger audience as holiday business is too fragmented due to traveller choices of off beat locations, city breaks, short tours and theme based holidays. Airbnb found a space in the segment which was very similar to vacation rentals but made this a opportunity business as "city rentals" and also deviated a plan to even share a room / bed in the house not restricting to whole place. The brand became popular as it was not just a accommodation but there was "social" angle to the traveller experience to stay with a local and cutting cost of his travel compared to expensive city hotels.
Google also did it earlier it was not the first search engine it was seventh search engine. So the future of entrepreneurship is more of improvement and process and leverage of powerful technology to make big brands. I would also like to share the thoughts of Jeff Bezos here :
It’s good to be unique. But it’s even better to put a unique twist on something that’s already been proven to work. “We watch our competitors, learn from them, see the things that they were doing for customers and copy those things as much as we can.”