Your Approach On Having a Downloadable Content (DLC)

Okay, my vision is to make a game that expand as times goes by.
Giving fans service by creating new content every 3 months or 6 months time frames.
New missions, new quests, new levels.

It's not an "unlockable" stuffs where when you buy an in-app store, then it will be unlock and available to players.

Here's my thought.
Simply an UPDATES.

But, here's my CONCERN.
If the game is 5GB.
It will be ridiculous to release an update of 5.5GB where the players need to download again.

So, a rephrase of the questions.

How is your approach to this kind of updates/patches to games powered by Unity3D?

 

Asset bundles

 

How do you MERGE that into the existing game builds?
A programming outside Unity?

 

Asset Bundles are built in unity. search for Asset bundles in unity docs

 

http://docs.unity3d.com/Manual/abfaq.html

 

Thank you for pointing out.
It seems that it is a PRO only.