Penetration and competition, really. The twitter feuds and the fact that your grandmother still checks her feed every day. Facebook itself isn't competitive, more a glorified e-mail (in my experience, anyway) and farmville is, believe it or not, niche.

I played so much Doom as a teenager, my mum woke me one morning for school and asked what I wanted for breakfast and I murmured that I wanted a shotgun and two shells.

I had to make do with the SNES version though, which had no saves. The only way to play it was to dedicate several hours of your evening and go through the entire episode in one go.