If the SAD is taken from one a or a few single crystals, the diffractogram depicts a regular pattern of bright spots. Since the diffraction pattern can be seen as a two-dimensional projection of  reciprocal crystal lattice, the pattern can be used to measure lattice constants, specifically the distances and angles between crystallographic planes. The lattice parameters are typically distinctive for various materials and their phases which allows to identify the examined material or at least differentiate between possible candidates. 
Even though the SAD-based analyses were not considered quantitative for a long time, computer tools brought accuracy and repeatability allowing to routinely perform accurate measurements of interplanar distances or angles on appropriately calibrated microscopes. Tools such as CrysTBox are capable of automated analysis achieving sub-pixel precision.
If the sample is tilted against the electron beam, diffraction conditions are satisfied for different set of crystallographic planes yielding different constellation of diffraction spots. This allows to determine the crystal orientation, which can be used for instance to set up the orientation needed for particular experiment, to determine misorientation between adjacent grains or  crystal twins. Since different sample orientations provide different projections of the reciprocal lattice, they provide an opportunity to reconstruct the three-dimensional information lost in individual projections. A series of diffractograms varying in tilt can be acquired and processed with diffraction tomography analysis in order to reconstruct an unknown crystal structure.
SAD can also be used to analyze crystal defects such as stacking faults.