Linked from
The 12 pages that link to Missing satellites problem, each with the reason it gives.
Galaxy evolutionRelated: Its resolution bears on how small galaxies form and survive over time.
Galaxy rotation curveRelated: Small-galaxy rotation data help test the structure of low-mass halos.
Dwarf galaxyRelated: The abundance of faint dwarfs tests predictions for small dark matter halos.
Galactic haloRelated: It asks why many predicted halo substructures lack visible galaxies.