This could be temporary. As the marketing ramps up even more, the awareness should expand.
It might be temporary, but Dr. Strange is probably their riskiest release yet due to the underlying subject matter/theme. I can see it starting slow, with word of mouth being the key to its success if it is deemed to be a good movie by viewers. Unless it is Potter or Hobbit/LOTR, the fantasy/magic genre is a tough one to get traction with.
You think Dr. Strange is a riskier release than Guardians?
Yes. The underlying theme for Guardians as a space adventure has been shown to work. Magic/mysticism is a much more difficult approach to attract viewers to. Potter succeeded because it had a huge following from the books already. I have been polling my co-workers, and even the ones who are fans of Cumberbatch from Sherlock have said they are waiting to see what the word of mouth is. If it is good, some may go, but others have said they will wait for Netflix instead (including the two that thought AoU was great ) as they do not care for magic/sorcery films. They all went to GotG.......