HD DVD enters & remains in Amazon's Top 10 DVD list

Just a few months ago, the Blu-ray edition of the Casino Royale managed to enter Amazon's top 10, making it the first HD title to enter Amazon's top 10 selling movies.  Even though Blu-ray seems to be selling way ahead of HD DVD going by Nielsen Videoscan, the HD DVD edition of "Planet Earth - The Complete BBC Series" has entered Amazon's Top 10 around two weeks ago and is currently ranking at #6 at this time of writing. 

One thing interesting about this title is that each time I checked the ranking of its Blu-ray edition, it has always been lower than its HD DVD edition ranking, with the Blu-ray edition ranking at #9 at this time of writing.  There are no other HD titles in Amazon's 100 at this time of writing to make other comparisons.  On the other hand, with Blu-ray selling far quicker in retail stores than HD DVD, it would be interesting to what percentage of retail store Blu-ray sales are actually discs bought with vouchers included with sales of the PS3.

According to Ultimate AV, this BBC HD DVD reached #4 on Amazon's top selling DVDs with the Blu-ray even further back at #17 at the time.  Unlike the Casino Royale disc, this BBC title does not come cheap either with the multi-disc series priced at $69.95; around triple that of a regular DVD!  On the other hand, if one can afford the price of the HD DVD player, this does not seem much extra as something to try out the player and HDTV set with