Ahhh....
And you have some ?real? figures to back your claim, right?
Yup, didn't think so.
Yeah. Well, we don't have many hard figures to support either side, but there are enough vague figures to create a sort of marshmallow of truth.
As I said above, TESNexus has registered about 1.2 million unique visitors. That's indicative of pretty high sales, especially given that many PC users won't use mods (Though I have absolutely *no* hard figures to back that one up)
Oblivion ranked top of sales charts for long after its release, and I believe got very high in the steam charts when it was released there.
Now, armed with Oblivion's relative position in the retail charts, there are a few figures. A quick search for the best selling games of 2007 brings up a few details (Though the data itself is far from accurate, due to there being very few sales figures released, the sales numbers that there are there do tend to be accurate), giving us numbers from 2.25 million (WoW: BC) to 236k (Er, The Sims 2 Pets Expansion Pack). Given that Oblivion ranked closer to WoW than The Sims, at least to my recollection, that gives an estimated figure *in release year* of significantly higher than the about 300k a 90/10 split would give. And, crucially, no tracking, ranking, or just raw data (from 2007, anyway) took into account digital distribution (indeed, very little does today), so the numbers I'm working off are very likely artificially deflated.
So yes, I have some real figures to back up my claim.