The SW canon always seemed like a farce to me, since George Lucas said the concept was based on how Star Trek treated it's tie-ins!
But he only said that much later. There was a big gap in original SW fiction after "Splinter of the Mind's Eye", the Han trilogy and the Lando trilogy. When the new "EU" books started up there was a "Starlog" interview where Lucas noted the almost-mainstream success of hardcovers such as "Spock's World", which didn't even have "Star Trek" on its spine. And bookshops would display EU timelines suggesting that all the forthcoming SW books really, really happened. Of course, SW only had the three movies and two Ewok adventures as live-action "canon".