It means that social media wise (which is pretty much the only thing WE can track), where Deadpool was a phenomenon, SS is making way bigger numbers (we talk here FB, Twitter, YT+FB views for trailers, promos). In fact, SS is outpacing any movie ever released on social media. It's total promo materials views are higher than any other movie, and that is before it even got released. BO.com just made a Twitter comparison for this past week and it is so far ahead of any comparable title (Deadpool, Civil War, Ultron) it is ridiculous. Of course, social media is dominated by the younger demo, but even so, for this to defeat established franchises like Avengers or Star Wars, while not being a sequel, is amazing. That is why it seems to me that 100m looks like a joke.
As for the GotG comparison... well, there's really no comparison. It's numbers look pretty pathetic compared to the SS awareness/hype.