I should personally think that the defeat of Louis XIV at the battle of Bleheim by the Duke of Malbourgh in 1706 was a very important imperial turning point for Britain- not only had the British defeated their main rival on the continent, but they had also left the Dutch and the Holy Romans indebted to them, humiliated the German state and significantly crippled Spanish power. Since it was the Spanish navy that was making the British resort to sponsored Piracy, this move would have potentially opened up the Americas to us British and would have let companies like the Hudson bay and east india company start up proper trading links which were secure.
Ikki, don't neccesarily think that the Americas were Britain's apple- the east was also very important due to the potentially larger (at the time) gains to be gotten from trading with the Qing dynasty in China and the Mughal empire in India. Also, it allowed to Brits to provide pressure onto a growing Russia which could threaten their future interests. Africa and Asia were Britian's major imperialist stomping grounds before North America, and the importance placed and excerted on and by British African and Asian prosessions since 1776 (not to mention that the British empire was still powerful even after the loss of North America). Also, Britain did not consider it economically viable to actually take a large colony in South America (although they did own a vast amount of stocks in Venuzala, and I would argue that this practically made it part of the British empire). We cannot understate the economic and strategic importance played by Britains' North American colonies in feeding Britain cheaply and providing a brilliant source of revenue for the British economy, but in the long term I would say that Asia was more important to them.