Star Wars as a franchise seems to be getting less and less popular among many casual fans with each new trilogy. PT was average and ST was a complete shit. However, bad advertisement is better than no advertisement, so perhaps at least the new stuff reminds the new audience that the franchise exists, which inevitably leads them to OT.
Even without the new films, there have been plenty of Star Wars video games coming out in the past three decades that kept the whole thing alive. Nowadays, video game audience is almost as big as film audience.