Double XP Events

Info
Double XP Weekend is a promotional event that rewards players with twice as normal experience towards Player Levels (and Prestige).

The first of this event was introduced on September 7th, 2012.

Official Announcement - 09/07/2012
''This weekend you’ll find that you’re earning DOUBLE XP throughout your Outpost! If you’re looking to gain some (or a bunch) of levels, now is your chance to do it fast. Earn more XP as you complete jobs, collect taxes and complete missions. -- gromper''

Source: http://battlenations.com/forums/topic/event-double-xp-weekend/

Effect
Quite simply, anytime XP is rewarded, the player is instead rewarded twice the usual amount. As the official post indicates, job rewards from shops, mission rewards and the XP gains from taxes are all doubled.