The decision by Southwest Airlines Co (NYSE: LUV) to introduce baggage fees is expected to significantly boost its profits, according to a Wall Street analyst.

Beginning Wednesday, Southwest passengers will no longer get two guaranteed free checked bags when purchasing a flight. That prior rule is disappearing as the airline starts charging fees for checked bags for the first time ever.

Southwest Airlines has revealed how much checked bags will cost customers, as the carrier's new fees go into effect this week. It'll look quite similar to other airlines. Starting Wednesday, Southwest will charge most passengers $35 for their first checked bag, an airline spokesperson confirmed to TPG early Tuesday.