There are many advantages that MIG welding has over other welding types.
In this article we will discuss quite a few of them.

• First of all it is fairly easy to learn MIG welding.
  You can become pretty good at quality welds in a short amount of time.
  You can buy a decent MIG welder for under $500.
  Also, many of these machines will be able to run off of a standard 110v outlet.
  Cleanup from a welding session is minimal.
  
• The next advantage is speed.
  Because a solid continuous wire is used there is no need to change rods.
  There is also no need for chipping the weld, as the amount of slag is minimized.
  Quality welds can be produced faster that most other welding types.
  You should be able to achieve a higher output of work compared to most other types of welding.
  
• The elimination of flux in MIG welding will help prevent slag defects in the weld.
  
• The shield gas helps protects the arc which eliminates the need to frequently replace the electrode.
  This will also help prevent weld splatter.
  
• It is easier to weld thinner materials.
  
• Can be used on a wide selection of metals, including stainless steel, mild steel and aluminum.
  
• The welding process can be either manual or automated.
  

So as you can see MIG welding has many advantages that make it accessible to the beginner.
Before closingI would also like to say that as with any type of welding you must read and follow all safety precautions and documentation that comes with the machine you are using.
Failure to do so may result in serious injury.