They maybe wanted the buzz to help, but it seems like it may have backfired. From what I've seen, the movie seems to be well received by the GA, but to many, it will probably be just another superhero movie releasing only ONE MONTH after Captain America, they maybe should have released it later, around summer.
Hell, I don't know, I love Spidey to death so I don't care about Cap America being released a month before, but it seems obvious people are not rushing to see it as I thought they would, the WOM will probably be better than for TASM, so who knows, it might end up catching up.