re: What made "Lost" so captivating?

From the storylines, to the production quality, to the characters, it was such a well done show. Very few weak links and it would just constantly captivate the audience. It had that element of mystery, drama, and action. It literally had something for everybody and there was a character everyone could relate too. Lost was also one of the first shows that had such an international cast. Plus, it was such a unique concept. The show's use of flashbacks and Easter eggs was kind of groundbreaking at the time. It had its own universe and fans were eager to dig through it. Off the top of my head, there wasn't another show like that before.

One thing I believe is really important to the success of Lost is the writers knew what their timeline was to finish the show, so the flow of the seasons towards the finale was a little smoother than you'd find with other shows that reach that point.

Let me also add that it found it's success around the same time that iTunes & DVR became popular. So people were able to watch episodes over again or in a row. because of that, you could pick up on many more things about the show.