Very interesting article about the worlds youngest self-made billionaire, one of the co-founders of Stripe:- http://www.bbc.co.uk/news/business-41859941
People often say that the best ideas have already been taken but this is not the case. There is still money to be made even just improving an existing service/product and marketing it better.
It all comes down to drive, skills and marketing - you dont need to re-invent the wheel to make big big money. The story of the 2 Irish brothers is inspiring.
Nice way to makeup for the potential loss of billions on their FB idea:- http://www.telegraph.co.uk/technology/2017/12/02/winklevoss-twins-become-first-bitcoin-billionaires/