I think media sales ,depends on sales of stand alone burners support both formats and marketing of some brands in combination of computer burners spread.
-Here in Greece till end of 2003,sales of DVD+R media were
very low ,even many computer burners support them .
This happened because, at first, the few cheap home burners not support them, at second, DVD home players have many problems in playing pure DVD+R.
-Now thanks most to cheap LG,Sony (and some second class) home recorders, dual format burning is preffering more and more -This moment sales of DVD+R media is 50% each format here.
Athough Philips sales remain at top of sales among cheap branded machines ,only support DVD+R . -Due spread of cheap computer burners , many people learn about dual formats ,so next step is looking for home DVDrec to support both , due also in small difference in retail price. So shares of DVD+R sales maybe increase ....