The World Hockey Association is a now defunct professional league that existed in North America from 1972 to 1979. Major pro like the National Hockey League, the WHA posed threat to the NHL by signing some of its stars and good young players and by establishing itself into markets still unexploited by the NHL that had or had the potential to develop a strong hockey culture. It revolutioned pro ice hockey in North America by drafting and signing top European talent and by introducing very high salaries for players, including a five years, one million dollars contract by the Winnipeg Jets for Bobby Hull, a colossal sum at the time. The franchises were very unstable however, and usually short-lived, sometimes lasting less than a season. The league would fold in 1979, promoting its remaining four most succesful teams to the NHL (Edmonton Oilers, Hartford Whalers, Quebec Nordiques and Winnipeg Jets) and having the other two teams left, the Birmingham Bulls and the Cincinnati Stingers, fold along.