The problem: if you have a small satellite, no more than 5 kilograms, getting it into orbit is hard. Nobody makes rockets that small, so you have to beg for rides on much larger rockets. This typically takes years, you can not choose your orbit, and if your satellite is seen as potentially dangerous (say, if you put thrusters on your satellite to move to the orbit you want) most launch providers will refuse to carry your satellite. In theory you could buy the entire rocket, if you had several tens of millions of dollars. (If you're reading this, you probably don't have that kind of budget.)
Our solution: make rockets that small. One launch, one satellite. A few months for regulatory review, then your payload is up. You choose the orbit. Nobody can kick you off the ride. Only $250,000. (Many academic missions can get NASA's CubeSat Launch Initiatve to pay for a launch. For everyone else, ask about our payment plans.) We aim to be the FedEx/UPS/USPS of satellite launch: if it fits the CubeSat specification and is legal to put in orbit, it launches, for one flat rate*.
Why is nobody else doing it: because small rockets are inefficient, making it difficult to make a profit. At least, if you do it the way it's always been done; we have a suite of technologies to optimize small launches so we can do it profitably. There are other rockets under development, mainly for 20-500 kilogram payloads, which is still too large for the popular CubeSat standard which we address. At just 5 kg, ours is the smallest rocket, as measured by payload to LEO, under serious commercial development that we are aware of to date.
*Not meant to imply endorsement from the USPS.