CEO Peter Beck told New Scientist that, if you want to launch a satellite into space, "you pretty much have to write a check for a billion dollars." In addition, there's normally anything up to a year's wait should you wish to use a facility that's owned and operated by the big boys of space exploration. By comparison, Rocket Lab wants to run 100 trips a year, using those economies of scale to bring the cost down to just $5 million per launch.
The company was originally founded in New Zealand, but it's not home pride or a Lord of the Rings-based reason why the location was chosen. Instead, the country's "high inclination and sun-synchronous orbits" make it ideal to get spacecraft up and away quickly. In addition, New Zealand doesn't have excessive amounts of air and sea traffic, so the company doesn't have to worry too much about imposing on the locals.
If everything goes to plan, the base will be up and running by the end of this year, after which point the company will start testing the Electron. That's the launch vehicle that's being powered by Rocket Lab's Rutherford Engine, which uses 3D-printed components and a battery to increase the efficiency of its liquid fuel propellants.