An innovation which has made nanosats popular is standardization. An example is the cubesat, made in units of 100 mm cubes, weighing no more than 2 kg each. The standard units allow easy manufacture and packaging for launch of multiple satellites. Cubesats can be piggybacked on launches of larger satellites, fitted into empty spaces. This is also a very familiar size, being about the width of a brick.
Nano-satellites tend to be in a low earth orbit, so they can capture higher resolution images, and use smaller radios, but this requires ground stations which can track a moving target.