# If airliners profit by moving luggage from checked to carry-on, why do some LCC gate-check luggage?

According to this answer, the less luggage is transported as checked luggage, the more "room" (in terms of weight) there is to bring along cargo, and thus more profit.

At the same time, some LCCs have the practice of gate-checking a bunch of bagage, essentially moving stuff from carry-on to checked luggage. It seems to me that that too is motivated by profit. But I'm not sure how.

These two practices seem to be contradictory, since they move luggage in other directions. While I can see the profit in the former, I don't directly see it in the latter. So what is the LCC's motivation to gate-check luggage?