Anisotropic magnets have a much stronger and more stable magnetic field then common, Isotropic magnets.
This extra step makes all the difference
Magnetic material crystals, in powder form, are magnetized so they orient (face) the same direction. This maximizes their energy storing capacity.
The magnetized crystals are molded into solid blocks, which are then cut into individual magnets. The magnets are then magnetized a second time, which charges them to maximum capacity.
This double magnetizing process gives the magnet a stronger, more stable magnetic field, and makes the magnet Anisotropic.
Common Isotropic magnets are magnetized only once, at the end of the manufacturing process.
Because the powder was not magnetized before molding to orient the crystals, the magnets can't store as much energy and are weaker.