Why do apps take long to download on my iPhone 5?

I recently bought the iphone 5 (first time user of the iphone). I noticed when I try to install apps they take quite a while to download. What do you think is the cause of this? My internet is pretty fast… Some apps that would of downloaded very fast on my htc sensation is taking a while on my iPhone 5 now.

Depends on connection at the time. They are also installing so some apps are much larger then others.