Air Canada Revenue Management’s team is tasked with ensuring that the maximum
revenue potential is made on each and every flight we operate.
As it is known that a certain percentage of confirmed customers do not show for their flights, it is sometimes necessary to sell more seats than aircraft capacity.
Revenue Management uses a sophisticated system that uses “day of” and historical
information to monitor all flights in Air Canada’s system, calculating the acceptable level of oversell risk.
Hotels do it too -- in the 90's I worked for a hotel chain and helped integrate an airline vendor's revenue management system into the hotels central reservation system. Just like the airlines, hotels use past booking and seasonality/special event data to figure out how much to charge for rooms and how much to overbook to maximize revenue. Prior to the software, hotel managers did it manually.
Pretty much every industry that sells products subject to spoilage does it too -- a grocery store determines how much bread to order to avoid throwing away spoiled bread that didn't sell before it spoiled while avoiding running out (the equivalent of overbooking - the consumer wants it but can't have it). But grocery stores and airlines have the opposite problem - airlines can't control supply (in the short term), they have a fixed amount of product to sell so they primarily use pricing to control demand. Grocery stores control supply (within reason) so if demand changes, they can just order more or less product (but they can also alter pricing).
Maybe if you know what magic words to ask, and specifically ask them - but at that point, you should already know the answer.