Almost a year ago Google started testing a feature called Promotion Extensions in text ads. This test must have gone well, as Google is now rolling it out to the masses.
Essentially, Promotion Extensions allow you to display offers in your text ads without having to create all new ads. This can include a promo code, a percentage discount and a set promotional period.
This is a great way to test various offers, test urgency and more. This is currently being rolled out to all languages and currencies in supported countries within the new AdWords interface (neatly called AdWords Experience).
If that doesn’t get you excited, you may want to check yourself for a pulse.