It is normal when talking about Philip.K.Dick to start by mentioning he wrote Do Androids Dream of Electric Sheep on which the film Bladerunner was based. So lets not do that. Ubik is much less well known and I doubt very much will ever get made into a film. It clearly falls into the science fiction category being set in the nineties, which at the time it was written were thirty years in the future.
So with the passage of time Ubik has now become an historical artefact. It gives us an idea about what people in the sixties thought was going to happen in the future. As such it now merits the attention of historians.