Though no longer a borderline exploit, as when planetary interaction was first introduced in EVE Online's Tyrannis expansion, producing robotics still rakes in ISK hand over fist. Ten Ton Hammer Contributing Writer, Space Junkie, tells us how.
Robotics are a valuable commodity produced on planets in EVE Online. A critical component in the construction of tech two gear as well as fueling personal starbases. As of this writing, robotics is the most inherently useful (and thus, valuable) planetary material. I should make clear that they are not the most expensive (the end-tier station parts are worth more) but rather that they have the highest juxtaposition of price and sales volume. It is also produced with only a single planet, making it accessible to casual industrialists.
Read more about Business Models: Producing Robotics With Planets In EVE Online.