From an AP article covering the LOST finale, "The End":
Through the run of the series, there was much talk among its characters of being on the island for a purpose. As it draws to a close, "Lost" has sustained the eerie feeling (eerie for TV, anyway) that it was on the air for a purpose - a special purpose beyond selling products and filling time, or even entertainment.
Its cast, producers, writers and the rest seemed drawn to create "Lost," and keep creating it year after year, thanks to fate as much as show-biz urgencies.
Deeper and wider than any TV series should dare to be, it has been thrilling, captivating, confounding (and, at times, pretty tedious), while it challenged its viewers to think, talk and feel.