^ People sometimes purchase games they don't enjoy.  Does that mean those consumers aren't savy? If it is even possible for a consumer to not be savy then it puts a slight hole in your argument that sales and quality ALWAYS go together.  

Sales are the best indication we have that are quantifiable, but it's possible that they don't always correlate with quality(Otherwise a used market wouldn't exist period and rentals wouldn't be needed if consumers were always savy).  We don't assume that Wal-Mart has the best quality products because they sell more than anyone else, or that Macs are very low quality because they sell a lot less than PCs and I don't see why it's any different with games.  Quality is a very subjective term and depends heavily upon different users and consumers and their demands and expectations.  

For videogames, we have a used market. If someone doesn't like a game they can sell it or even give it to a friend. In both cases, they don't buy a new game, but buy a used on instead, which will not be reflected on the sales numbers.

Price, however, is a determiner of quality, but not in the way you think. Price is a barrier. If you want more people to try your product, then having an affordable price is how you eliminate that, then the product will stand on it's own two feet. You can make the best product ever and sell it for a million dollars, but who will want to buy that? People can't get it. So, is it really the best product if people can't get their hands on it. It gives them no benefit.

Let me quote someone else as he explains price with the PSP Go

Personally I love being able to play both types of games on my PSP. Games like locoroco are fun but I also sometimes want to play FFVII. IMO the line between a true handheld game and a 'console' port to the handheld is very thin. The failure I think in the PSP to compete with the DS has to do with the number and scope of games. Not because they weren't handheld games, but because they don't appeal to a large enough audience. I simply can't get the same number of good quality games on my PSP than I can get on my DS.  

@Smashcu2

I completely understand what you are saying. Sales are the best measurable and objective way we have of defining quality or value, I don't disagree with that at all.  I am saying that sales are not the ABSOLUTE measure of quality and can't be otherwise things like rentals and the used market wouldn't exist. 

If things that sell the best have the highest quality then why would anyone want anything else?  Why would anyone return this object of the highest quality or value?  Maybe unless quality and value was different for different people. Sales are the best way we have of measuring it but not the absolute end all be all. That depends upon the consumer and his or her experience and expectations.  Just because more people have a set of expectations or enjoy a particular type of experience doesn't make them any higher quality or value just more accessible, unless of course you are a company trying to make money in which case the largest amount possible is the best as the business wants great sales,  but we aren't, we are people discussing a hobby.    

In my humble opinion the problem is that Sony has failed to properly assess the market.  From my perspective I see three different types of handheld gamers.  One major and two minor.  The major handheld gamer is the child audience ranging from approx 7-15.

After this the only people left playing games on handheld consoles fall into one of two categories (excluding japanese, im unfamiliar with the culture and won't pretend to be).  These are the Minor categories, and consist of the left overs from the child category who continue to play these games and are now hardcore handheld gamers and the casual gamer (insert older gamer) that has been introduced due to nintendo's brain training series (among others) and clever marketing.

To give you an idea, my mum's best friend (who is i imagine about 65) wanted to buy a ds because she wanted to keep her mind sharp, however she didn't understand that you had to buy a "console" and then also the "game" in her mind she thought it was just all the same thing... ahh nintendo, we love you.

Sony has failed to properly address the core handheld market of the children by offering products similar to there home consoles which target 12-25 as the core audience, and has not even considered the casual audience.

Instead sony seem to have decided they would simply create there own new handheld segment, which as we can see has proven to be most successful.