For me, pretty much all of the options apply. The novelisation ofStar Trek First Contact was the first book that I ever read completely, I had started to read other books before that but I found reading very boring up until that. It was also in english and it was the summer before we started english classes at school, I had learned enough english from watching tv that I understood about 99% of the words in the book, had to check only a few word from dictionary. After First Contact I read the novelisation of All Good Things and after that the novelisation of Generations. So at first I was intrested only in the novelisations of the episodes and movies, and as I read more I also got more intrested in reading in general as well but mainly I read only Star Trek. I started to read all Star Trek novels that I could get my hands on because I was intrested in new adventures that I had not seen in tv.
Somewhere around 2001-03 I started to lose intrest in reading Star Trek, and apparently I lost a box filled with Treklit when moving, but I did go often to a bookstore and out of old habit always checked the Star Trek books but never bought any. Some of the Star Trek books never left my own bookshelf even when I never read that, one of them was First Contact as it was the first book I ever read. About year and a half ago I saw Christopher L Bennetts DTI book on a bookstore and decided to give it a try as it looked intresting. After reading it I realised that there has been a lot of things happening in treklit-verse and that I'm still intrested in Star Trek, so I started reading treklit all again. I buy the newest books and go through used-bookstores for the older books that I never read (and sometimes books that I have read but did not own them anymore). I even found some of the old Young Adult series books for euro a piece (havent had a chance to read them yet), I remember seeing them in bookstores back in the day but thought that I was too old to read them, even though as I understand they were written for teens and I was a teenager back then.
So basically I read because I enjoy reading and because I want to see what happens next in Star Trek.