Prochlorococcus

Prochlorococcus is the smallest and most abundant photosynthetic organism on Earth. Though each cell is less than 1 micrometer across, its total population is estimated at 3 octillion (3×10²⁷) - roughly 10 million Prochlorococcus cells for every human on Earth. Collectively, they produce about 5% of Earth's oxygen.

Prochlorococcus was only discovered in 1986 despite being the most numerous photosynthetic organism. Its small size and ordinary appearance made it invisible until flow cytometry could detect it. The business parallel is overlooked value - important contributors that go unrecognized because they're small, numerous, and don't match expectations of what 'significant' looks like.