We don't often highlight Southwest bonus offers because, frankly, Southwest doesn't often offer noteworthy bonuses. On the scale of promotional activity, Southwest usually scores somewhere between "Rare" and "Infrequent."

But the Texas-based discounter has rolled out a new promotion that qualifies as the exception that makes the rule. And it's a dandy.

Southwest is offering Rapid Rewards members a free ticket for flying two paid long-distance round-trip flights between September 1 and November 15. (For purposes of this offer, 'long distance' is defined as flights of 1,250 or more miles each way, including stops and connections. There's a list of eligible routes on Southwest's website.)

Qualifying tickets must be purchased on southwest.com. A maximum of two awards may be earned during the promotion period.

Normally, Rapid Rewards members earn a free round-trip after every eight paid round-trips, so on the scale of promotional generosity, this limited-time offer rates as an unqualified "Go for It."