Which are you calling the "Big 4"? I'd have said there were five; has one dropped below the others recently?
To me the "Big 5" are Microsoft, Apple, Google, Facebook, and Amazon. I didn't realize there were different lists. What's yours? :-)
edit: perhaps this is a regional difference; are you in the Bay Area? I imagine that Microsoft has less of a presence there, and perhaps Netflix is a bigger deal down south than they appear to be here in Seattle.