okay.. now here's a very rough set of calculations to maybe help understand the 1.5 million shipped discs statement..
it involves taking amazon data now we can see stock levels. I took a reasonably big catalogue title, King King which is ranked between 3-4000 right now and it looks like it sold about 60 copies over 2 weeks. The overall stock graph shows a consistent overall stock level of around 14,000 units.
now, let's use those 60 units as a ballpark average figure for each title, bearing in mind some will sell a lot more but the ones in the lowest rankings will sell very little in a 2 week period. There's about 150 titles.
150 x 60 = 9,000
9,000/2 = 4,500 per week
4,500/14,0000 = 32 % of stock level sold.
32% x 1,500,000 = 480,000
now, the 1.5 million figure was over two months ago so it doesn't tally up to Jan/Feb '07 figures but then the 60 average could be even lower than that as way more titles are below King Kong than above.
like i said, it's very all very and generic with the ballpark figures but make of that what you will...