As near as I can tell, Southwest Airlines has three kinds of sales, where fares start at $39 , at $49 or at $59.
The new 7 Days of Deals sale is a $49 sale, which means that’s the bottom rate for short flights such as Bradley to Baltimore.
Tickets must be purchased at least two weeks in advance by Thursday, April 1, 2010, at 11:59 PDT for travel between April 12 and June 10, on Mondays through Thursdays. The fare is not valid around the Memorial Day holiday, between May 27 and June 1.
The fares don’t include taxes and fees, which bring the price of the Bradley to Baltimore trip to $119, round-trip. Not bad, plus you get to check two bags at no extra cost. (I will never tire of reminding you of this.) But I like the $39 sale better.