If you compare it to previous iD franchise's, RAGE is a total flop.
Can anyone tell me what the first week sales numbers were from DOOM and Quake?
I don't know what the first week sales were, but over the entire product life cycle, DOOM 3 sold about 3.6 million units worldwide (all platforms), DOOM 2 sold about the same and DOOM sold 2.8 million PC copies (excluding all the various ports to numerous platforms like SNES, etc.).
I'm guessing this also excludes shareware sales - according to id's website tens of millions of shareware copies were sold:
"Selling millions of copies and chalking up tens of millions of downloads as shareware, DOOM remains one of the most popular PC games ever. "
Some of the Quake information seems to be incomplete, but from what I can gather, Quake 4 sold about 275,000 units on Xbox (PC sales not provided), Quake sold about 300,000 units on N64 (other platforms sales not provided) and according to id's website, the total for Quake 2 was over 1 million units for all platforms:
QUAKE II was a watershed hit for the company, selling more than one million copies, despite it's steep hardware requirements.
http://www.idsoftware.com/business/history/
http://gamrreview.vgchartz.com/sales/1819/quake-4/
http://gamrreview.vgchartz.com/sales/1820/quake-ii/
http://gamrreview.vgchartz.com/sales/1818/quake/
http://gamrreview.vgchartz.com/sales/7289/doom-3/
http://gamrreview.vgchartz.com/sales/6233/doom-ii/
http://gamrreview.vgchartz.com/sales/6232/doom/
Judging by the excellent first week sales, it seems likely that RAGE will sell at least a few million units over the course of the next few months, resulting in one of the most successful id game releases to date.