It's quite extraordinary that both The Times and the BBC reported that 4 billion people watched the opening ceremony of the Olympic Games.
First of all, I doubt if three quarters of the world's population has access to a TV set. Then, I suspect that not all of those people sat down in front of a television set at 1pm on a Friday in the UK, 2pm in Europe or 8am in the US (this suspicion is supported by the fact that many of them have jobs to go to or to do). Added to this is the fact that a large proportion of the world just aren't interested in this sporting event.
This type of exaggeration does television no favours; the viewing figures for traditional broadcasting have only ever been approximated and when they are accurately measured, viewer for viewer, they come as such as shock to the broadcaster that they can the results for fear of spooking advertisers.
However, it's glib, generalised claims like this (and their disgraceful reporting by news organisations that should know better) that are playing all of those advertising dollars straight into the hands of companies who can be accountable for what audience it delivers - companies like Google.