Why create something from scratch if you can buy a ready-made startup? Capitalization of the same Greencoin today is just a penny for Greenpeace. It seems to me that it is easier for them to buy ready-made than to develop their own.
Usually, large corporations do just that - choose a promising startup and buy it. It is cheaper and more promising than creating something of your own.
Facebook itself bought Twitter in its time, and now everyone uses it, they just saw the prospects in due time.