The only uncertainty in my argument is that we don't know if the BR movies sold to PS3 owners are mostly to movie watchers that bought a PS3 as their player or gamers that occasionally bought a movie.
This really isn't true.
For example, can you prove that the majority of BluRays sold were not sold to PS3 owners?
Or can you cite the relative number of those sales that were part of free give aways or special offers - especially the 5 free BluRays given to new PS3 owners?
I could go on, but can illustrate the problem with just these two. In order for your 10:1 number to work, you must assume that there is a 1:1 correspondence between number of BluRays sold and number of standalone BluRay players. In other words, you first subtract the number of standalone players from the number of BluRay disks sold and then assume what was left over was sold to the PS3. This is different from the actual assumption you say you make later, but related in a sort of roundabout way.
On the other hand, it is just as likely that for any given title the majority of disks were sold to PS3 owners and that the standalone owners bought few movies - meaning that the majority of the disk sales should be counted against the PS3 and your "subtract the stand alones" method is invalid.
It could be equally postulated that the majority of BluRay sales were really the special offers included with PS3s for several of these months. Basically, you could use this data to set upper and lower limits, but you will find that these limits fluctuate between your 10:1 number at one extreme and my 1.35:1 number at the other. The real value can lie anywhere between.
The assumption that BR standalone owners would buy as many movies as (or more than) HD-DVD owners is very sound.
I do not think this is a good assumption. Movie sales were driven by sales and releases. If you go back and review the weekly numbers, you will find that a BOGO at Best Buy could push one format over the other very easily. In any given week, a new release could push one format over the other by a large margin. Packaged deals like the offer I mentioned for the PS3 also heavily influenced these numbers.
In other words, the statistics at this point were dominated by demographics and fluctuation. After a long time, this type of thing gets averaged out statistically. However, that takes very large samples. This is actually one method that the PS3 helped BluRay. It's much larger install base helped "smooth" the random fluctuations towards the end such that it won on a consistent basis regardless of BOGOs or release title. Studios could say to themselves "Hey, even if it wont sell 10 movies per console, it is obviously selling movies. We can make a profit here." It gives them a reason to commit to the format.
Once you include the advantages HD DVD had early on in their lifetime vs. BluRay I think you would have seen a far different landscape if Sony had tried to compete based on standalones - even heavily subsidized ones. One of the major advantages was the relatively painless modification of existing DVD production lines to HD DVD vs. the relatively costly BluRay upgrade. See #2 below for a more complete explanation.
The PS3 has several aspects that make it very appealing to CEs and movie studios that a standalone will never have.
1) Not only movie buyers will buy one.
Generally, the hardest part of getting a new format off the ground is early adoption. Now, a subsidized player is going to be purchased solely for the purpose of playing movies. That means someone who is "happy" with DVDs will not buy one. Think about that for a minute.
Even if a person who purchased the PS3 just as a game machine only buys 1 or 2 movies, they still buy 1 or 2 movies. It gets players in homes and helps break the initial early adoption barrier. It gives you a new market to sell your product too. Both are huge in the eyes of companies trying to figure out how they are going to profit from a new technology.
2) There is predictable future growth associated with the console.
Look at this from the perspective of a major studio. It takes money to invest in a new production line. They want reasonable assurance that they will get a return on that investment. Even if BluRay had failed horribly, the PS3 is currently following a growth curve similar to the PS2. Basically, you are guaranteed a niche market for your product, even if you miss the mainstream market you had aimed for. All Sony had to do was sell enough PS3s to guarantee a return on the investment for movie companies.
Without this predictable growth, Studios would have had to choose based on maximizing profits. HD DVD was actually a much cheaper conversion for production lines. It would have been a far safer bet to go with them over BluRay. I seriously doubt the studio support would have been like it was had Sony not been able to give this type of assurance for return on investment.
3) "Fellow" CEs do not have to compete with your subsidies.
This is probably the largest single factor in what killed HD DVD. Toshiba could afford to heavily subsidize their players. Companies like Oppo could not. You will note that Oppo and others quickly dropped from the HD DVD hardware manufacturing circle because they could not produce a product that could compete at the prices Toshiba was subsidizing their players too.
On the other hand, Sony's fellow BluRay members did not have to do this. There is a market for standalone players even when good alternatives exist. Not everyone is going to buy a PS3 or a HTPC to play a movie. So instead of having your standalone at $500 vs a heavily subsidized $100 Toshiba player sitting side by side in the HD DVD section, you have your standalone at $500 vs. Sony's standalone at $500 sitting side by side.
Sure, an informed customer might take the heavily subsidized PS3 over your standalone - but CE companies were actually finding ways to make money on their standalones with BluRay. They really weren't with HD DVD.
At the end of the day, the PS3 gave the studios and Sony a way to commit to the format with very little risk to themselves. More than anything, that was a huge advantage in the format war.