A mixture of things.
- Early announcement, focus on nostalgia and great content.
- Great pricing and options.
- Xbox One PR disaster, countered by Sony's PR triumph.
- Nintendo failing to capitalise on the Wii's success.
- Strong 1st party content for the PS3's twilight years, promises of a continued strong exclusive push.
They weren't arrogant. They weren't taking a victory for granted. They continued to actually push for quality. They treated the consumer with respect. They consistently supported their developers.
I've not watched the video, but I'd assume that's the whole of it.