The Bear Brick website indicates each brick can produce 16,000 btu's. I'm troubled by the word "can" as opposed to "will." It might actually produce less. (broken link removed to http://www.bmfp.com/bear-bricks/bear-bricks.html)
16,000 btu's is about the heat content of a very well-seasoned log (8-10% MC) which weighs just 2 pounds. I have 3-year, woodshed firewood, (very dry) and I grabbed a piece of aspen (popple), just about the lowest heat content per volume wood around, and a split of a 4" branch, 16" long, weighed 2 pounds. This means that 4" branch produced 2 splits, equivalent to 2 Bear Bricks.
24 Bear Bricks/day, assuming 16,000 actual btu's/brick, works out to 384,000 gross btu's, and assuming a 65% stove efficiency, 250,000 available btu's, which is 10,400 btu's/hour heat output.
If you use the Hearth.com heat loss calculator, a 10' x 10' x 8' single room (100 sq ft), one exterior wall (assumed standard room), has a heat loss of 5,050 btu's/hr. Based on this calculation, 24 Bear Bricks per day would heat about 200 sq ft of living space.
https://www.hearth.com/calc/roomcalc.html
Obviously, this is a very rough calculation, but it does start to give an idea as to how many Bear Bricks a person might need to heat a house. Do the heat loss calc, and that might explain why so many bricks are being burned.
Also be sure to compare cost with current cost of other fuels or electricity.