High definition market share numbers have always been opaque to me.  The proponents of one format or another would always talk about sales in terms of precentage increase from previous sales or market share compared to DVD.  Techniques like this are almost exclusively employed when the raw numbers are rubbish.

Home Media was one of the first places you could find real data.  Originally, I only saw the comparison of the top-20 sales numbers for BD vs the top-20 for DVD, a comparison that obviously would favor BD.  However, we've now been getting both top-20 percentage and revenue percentage numbers.  However, since BDs are so much more expensive than DVDs, especially older DVDs, you could expect the average sale price to be anywhere between 50% and 100% more expensive for BDs. 

Is revenue relevant?

Perhaps if BDs and DVDs were equally priced, BD owners would still make up that revenue by purchasing more movies.  This is pretty unlikely: there are only so many good movies out there, and if collectors really want movies, they'll buy them.

Consider an extreme case where a format came out that was extremely expensive (format B).  Say format A has 99% of the market in terms of sales but format B, with its 1% of the sales, has 50% of the revenue.  Would you then consider it misleading to say that format B had 50% market share even though format A was selling 99x as many copies?

Yet here we are with BD.  Let's make "market share" mean "revenue".  It's a very odd choice but it looks like it's something they were using for years.

It's certainly unfair. If we tracked video game hardware sales like that PS3 would appear to have more marketshare than Xbox 360.

Yes, it definitely would.

In a few places you can find the raw numbers.  Washington Post had a story about DVD vs VHS that talked about the number of rentals during a period.  Apparently DVD passed VHS in 2001 in terms of sales revenue, but VHS was more rented until 2003.

edit: the thread that tracks Blu-Ray market share says its at 10% at the moment, are you saying thats wrong?

Revenue can be relevant. Even if the price of item A is more expensive them item B. Its econ 101 in a sense. Example:

2 Products are competing. Product A is more Expensive, thus sells less then product B. If the perceived value and superiority of product A is high enough, its quite possible that even though it sells less units in comparison, that one can have a higher revenue (and possibility profit) over product B.

Generally, (I SAY GENERALLY, i know someone is going to be like "look at the Wii") higher priced items tend to have larger profit margins, mainly because when you get into higher numbers, its easier to add a few bucks with out a big deal. Ever wonder why when new Blu Rays come out, some stores for the first week well sell them for like 25 bucks, before raising them to 35 dollars? But do you ever see DVDs doing such a price drop now a days?

So the idea is that if the number of units product A sells, multiplied by the price, is greater then the value of number of units product B sells multiplied by its price, then in the end, what can be misleading isnt necessarily the revenue numbers, but using sales numbers to compare the general success of a product.

Granted, the economy is more complicated than this, but this is somewhat of an explanation of why revenue could be important.

Revenue and profit is only important in sustaining a business.

However comparing market share using revenue it is stupid.

There is a high fixed production cost associated with creating a DVD/Blu-Ray master disc for duplication. If a blu-ray movie sells a tenth as much as a DVD, the fixed cost per disc is ten times as high, and the blu-ray production cost is higher then DVD.

Plus blank blu-ray discs are significantly more expensive then DVDs sine it is still new and licensing fees are higher. Some duplication company on the web I found mentioned in their faq's that plastic blu-ray cases cost 5 times as much as DVD due to limited supply.

That's why blu-ray discs cost more.

If you measure market share in terms of revenue, BD gets about 10% of the home video revenue on average.  This is down from the 50% that Sony claimed they'd reach in 2008.  But in terms of "number of BDs sold vs number of DVDs sold", BD is well below 10%, probably closer to 5%.

I agree as this is obviously the case.  I can think of two reasons to do it:

(1) it inflates the "market share" numbers for the more expensive technology -OR-

(2) it is too difficult to track the numbers accurately and it is easier to track the revenue.

I think (2) is most likely the case.

in economical terms a market is described by it's total value and hence the most logical value for the marketshare of a product is it's revenue, the total amount of money people spend on a product

over here at vgchartz we are using product sales, because we are not vieving a market from an economical perspective

I dont think it is unfair per say. Every time a person buys a DVD they are not buying a BD. BUT, you can find most movie that are 1 year or older at WM for 9.99 or under. The cheapest I have ever seen BDs is 24.99 (regular Price), I think I saw some fro 14.99 on a doorbuster sale.