If this is a stunt for a movie or something, it is brilliant. It preys on so many psychological needs that people seem to have to experience the numinous.
That the man is portrayed as someone helpful in the dreams satisfies those who wish for a higher power to protect them, advise them, and provide answers to them in their lives. It also plays into those who seek for the feeling that their lives have meaning. If there is someone who has the power to enter your dreams, and that person has deigned to do so with you, then you must be worth that powerful person's attention and time. For those who haven't seen this man yet, the suggestion of it will cause them to see the man in their dreams, because they want the feeling of safety or significance.
However, the mysterious aspect of that can also play into any kind of paranoic thoughts. Even though the person is described as helpful, it is not a big leap for those who lean towards paranoia to suspect there is something sinister behind this phenomonon.
If you think of some of the other bogus schemes that have gone viral in the face of reason, such as "
The Secret", you can understand what I mean. This is some kind of combination of The Secret and viral memes from people like Whitley Strieber who believe that people are abducted by aliens, and remember it only from dream memories.
If this is contrived, it is pure genius.