1970's & 80's Sci-Fi Film Novelizations

[ITViking]

I'm a long time collector of... well many things really... but in particular Star Wars merchandise. Lately, I've been more interested in the early Star Wars novelizations, by Ballentine Books & Del Rey. I've learned that in producing his novelization (ghost written by Alan Dean Foster), George Lucas clearly had his own agenda and way the book was released was 'unconventional' for the era. So far I've learned a fair amount about the specific editions and printings but I'd love to know more about the industry norms at the time, and more what was typical of publishers releasing film novelizations in the 1970's and 1980's.

Also... what is a 'special printing'? Around the time of the release of Star Wars Del Rey cranked out somewhere in the neighborhood of 3.5 million copies of Star Wars in paperback. The first paperback printing 6 months earlier in Dec 1976 was limited to 125,000 copies. Between June and July of 1977 there were something like 8-9 additional printings, then all of the sudden in August 1977 there was this '1st special printing'... except there doesn't appear to be too much special about the paperback. Was there any common significance to a 'special printing'?