What's the point of retiring?

[JekkJekk27]

what are you suppose to accomplish by retiring your character?

[MountedRhader]

Extra xp when you hit 31, and you get to make an item of your choice statistically better. 

[Tears of Destiny]

Retire at level 15 or higher and you start over again at level 1 and keep all previously earned gold and items, as well as a chance to make a different character/fix a mistake you made.

Retire at 31 and you also get a comulative 10% bonus to XP earned per tick, as well as the above, and a choice to heirloom an item (So a Generation 11 would earn 2000XP per tick instead of 1000).

To see what heirlooming does, check the stickied thread above in the Beginner's forum for details. It makes an item better without increasing the upkeep.

[EliteDragon]

Some people also like retiring because at higher generations, you can:
1) Test out your character builds faster.
2) In the long-term, make builds that are more based around higher levels (above 30).