One could also call it Facebook's | Zuckerberg's Law: "Whatever I claim, divide by four" ...
Does this rule also apply to the number of Facebook users? Is it more like 300 million rather then 950 million?
That's what a few people on here have been implying. And personally I think that's quite likely. Seems like the stock markets have caught on to this as well: $FB is down again ... By Zuckerberg's law it should drop all the way to $10.5
I had similar experiences in managing facebook campaigns. The numbers simply don't add up. Also, many people are using several facebook accounts, especially when using games.
Does 20 ~ 25% coefficient seem about right based on your experiences?