Frontier Airlines is introducing a free checked bag promotion in an effort to poach former Southwest passengers frustrated by the airline's decision to ditch its longstanding "bags fly free" policy. Called "Your New Love,

Let down by the end of Southwest's free checked luggage move? Frontier is hoping to entice you onto their planes with a new limited-time deal.

Southwest Airlines will begin charging customers a fee to check bags. It's a significant change for the budget carrier, which built years of advertising campaigns around its policy of letting passengers check up to two bags for free.