Here's a stat I was thinking about and did a little research on. I think we can go ahead and make it a given that GOTG gets to $300 million.
Granted that Thanos and The Collector have been very briefly on-screen in prior Marvel movies, but only 16 films have ever made it to $300 million without the characters having been on screen before (in close to their present incarnation), being direct sequels to previous work, or, in the case of the Avengers, several works.
GOTG would be just the 7th film in the last decade to make this $ amount under those specifics, joining Avatar, Frozen, Passion of the Christ, Alice in Wonderland, Transformers and Iron Man.
The prior to 2004 entries, if you are curious, are: Titanic, Star Wars, ET, Spider-Man, Finding Nemo, Forrest Gump, Fellowship of the Ring, Pirates of the Caribbean and Independence Day.