No, from the same blog post: "Pratchett was not the only one with the soup adverts, I remember at least one Star Trek novel and a few non-franchise ones having

No, from the same blog post: "Pratchett was not the only one with the soup adverts, I remember at least one Star Trek novel and a few non-franchise ones having the same stuff in it. The whole thing was a holdover from the 50s or 60s, when practices like that were more common, especially with publishers of cheap genre fiction."