This is so dumb it's almost offensive. All companies don't peak in their performance at the same time. Look at one seven year old company and another. If their numbers are the same at that moment, what odds would you place on their numbers still being the same (+-10%) ten years later? Me, I don't put much money on that at all.
Well, we're still at the very early stages of social media on the web. As someone else points out in another comment: owning the complete social graph may very well be the most valuable asset ever. I think the potential market for Facebook can grow much more than just 3 times over the next 7 years.
Inflation has been low the last decade, but sure, that affects the numbers.
Social media is a nonexistant. It's something somebody at Facebook (or Twitter) dreamed up to hype and justify existence.
From henceforth I declare this movemenet DuncanIdahia - you may not have heard of us - but we're growing tremendously (we grew infinitely from 5 minutes ago to now).