Best ways on hosting a website with visitors from all over the world

Currently I'm using forge with some Linode instances to host a blog for a customer. The customer has over 150k visitors per day currently.

The site is stable and fast though I notice slower loading times from countries like USA, India or Australia / NZ. The most common reason for this is that the servers currently are located in London.

What would be the best ways you suggest to host such kind of a blog or getting it to a good speed from all over the world.