Server location is key and poor location choice is a common problem we see. It's really important that you host in the geographic location that is closest to the majority of your visitors.
That means if you're a Malaysian company serving mostly Malay customers you need to host at a location in South East Asia. If you're a US company, then host in the US and a Europe based business then host in Europe.
Generally the site will run 0.5-1 second SLOWER when the visitor traffic has to cross an ocean so this is really important!
South East Asia is a little different to most other locations in that countries are located close together and generally all connected with high speed, land based fibre optic - this means that you can safely host in nearby countries and not experience any speed loss.
For example for most of our SEA customers in Malaysia, Thailand, Burma and Vietnam, we recommend hosting in Singapore as their internet infrastructure is the best in SEA and many international fibre links route through there.
Not all providers offer hosting in all locations so before committing to a provider make sure the servers are located in the right location for your business.
**NOTE if you're serving an international audience then it's really important you use a content delivery network (CDN). A CDN is a distributed network of servers around the world that host your content that will reduce the impact geographic location has on speed. Most top tier hosts have CDN services built in.