Sony Computer Entertainment boss Kaz Hirai has said that PlayStation 3's success cannot be judged after less than three years on the market.
"If you look at the growth of the installed base, it is slower than the PS2 was but it's pretty much on track with the growth that we had with the original PlayStation," Hirai told The Times.
"We also always look at our business as being a 10-year lifecycle for all of our platforms. It's kind of difficult to say whether a platform has been successful or not going into our third anniversary. The fifth anniversary and beyond is when we really start to say how's our trajectory looking?"
Last week Sony's European boss Andrew House confirmed that worldwide PS3 sales stood at 23.7 million since the console's November 2006 launch. Xbox 360 launched a year earlier and has sold over 30 million.
Hirai also rejected suggestions that DVD and even Blu-ray may be on the way out as digital distribution becomes more prominent.
"The death of physical media is a very nice conclusion, that seems to be nice to say, but its not something we're going to see soon," he said, pointing out that even in a few years' time 40GB PS3 games will take ages to download.
Sony will become the first platform holder to launch a digital-only console in October when the PSPgo launches, but Hirai said Sony was "committed" to maintaining the PSP-3000 and UMD businesses in spite of that - partly because of the need to continue serving customers in countries without the same rates of broadband growth.
"We're not going to deprive consumers in all those other countries," he said.