The Keurig K-Cup system is the most popular pod coffee system available, with the company claiming that 6% of all coffee made in the USA comes from one of their brewers. It was first introduced in 1998, and the Keurig company was bought out by the Green Mountain Coffee company in 2002.
The K-Cups that these brewers use are made from plastic with an internal paper filter. A wide range of coffee types are available (over 200 at present), as well as other drinks such as hot chocolate and Apple cider. These come from both other coffee companies and the Keurig parent (Green Mountain Coffee). Many of these blends are certified in the Fair Trade program, which works with the coffee growers to get them the best price for their coffee in long-term contracts that provide price stability.
Other hot and cold drinks are also available in K-Cup format, including teas, iced coffees, hot apple cider and cocoa.
The K-Cups cost around $0.65 each (based on a pack of 24). This price can be reduced by buying in bulk, but this system remains more expensive than others. Keurig does offer a $14 refillable K-cup (called My K-Cup), which can be refilled with your own coffee and reused. This only works with their home systems: it does not work with the business or commercial systems.
If you've got a household that drinks two cups a day, a Keurig brewer will cost you about $39 a month and $468 a year to run.