It wasn't overnight. ITA has been doing flight search since forever. In fact, they even had the matrix UI before Hipmunk (though it wasn't featured as prominent

It wasn't overnight. ITA has been doing flight search since forever. In fact, they even had the matrix UI before Hipmunk (though it wasn't featured as prominently): http://www.quora.com/What-is-the-company-that-HipMunk-copied-design-wise http://www.quora.com/What-is-the-company-that-HipMunk-copied...