Eh, definitely wasn't obvious to me. I mean what build is needed? In marketing? It was all over social media and tv for the past month or so. It's another origin film so I am not sure what build up you needed before the film came out. They didn't need to go with a viral campaign like others, I like what they did in their website like trying to explain the powers and how it worked for me.
First trailer was "eh" but it peaked my interest with the new style and how they stayed away from being associated with the first 2 films and thought it got better the more trailers they showed.
Again I like the sci-fi feel. Michael B Jordan, I like Kate Mara, I like Teller (especially after whiplash but I also showed concerns) and I like Thing being cgi.
Maybe it's just me but I never judge prematurely (to the best of y ability) on what's going to flop and what isn't based on trailers and production news (even based on marketing). I mean outside of the production rumors (they just turned out to be true) there were no signs this film would be reviewed this bad and flop. I didn't think it would be TDK or IM1 great but I at least expected TheWolverine good (70% on RT but most NTers hated it) or even MoS (56% on RT and I actually liked this film but understand why it's ranked that low) and Wolverine made ~$400m and MoS made ~$660m respectively worldwide. I could have seen F4 making at least $300m-$350m if the reviews weren't so bad or better yet, if the movie wasn't as bad (which was an unknown before we saw the film despite all the NTers who are fortune tellers and would love to say I told you so
despite most saying the same for DoFP and many changed their mind until a year later when everyone hated it now
Estimations isn't always right but there is a reason it was still expected to make $50m over the weekend before the bad reviews killed the film. It was even trending better than AntMan on some demographics. I honestly did not see it getting buried as bad as it did (I actually think the movie is bad but not as bad as most critics make it out to be).