The medium has numerous advantages:

First, it is compact, with far smaller storage costs than paper documents. Generally, a year of a periodical in microfilm form takes 10% of the space and 3% of the weight of its paper version.

Second, it is lower cost than a standard subscription. Most microfilm services get a bulk discount on reproduction rights, and have lower reproduction costs than a comparable amount of printed paper.

Third, it is a stable archival form. Most library microfilms use polyester with silver-halide dyes in hard gelatin, with an estimated life of 500 years in air-conditioning. In tropical climates with high humidity, fungus eats the gelatin used to hold silver-halide. In the tropics, diazo-based systems with shorter archival lives (20 years) are preferable, because they have polyester or epoxy surfaces.

Fourth, since it is analog (an actual image of the original data), it is easy to view. ( much like analog phonograph records having the sound waves carved into the vinyl) Unlike digital media, the data format is instantly comprehensible to persons literate in the language; the only additional equipment that is needed is a simple magnifying glass. This reduces the possibility of incompatibility and obsolescence.