Here’s an interesting graphic for you. The following shows the 5+ channel share from the 16th of July to the 16th of August.

There are a couple of interesting points from this graph. Firstly, it’s rather obvious how beneficial the Olympics were for Prime’s ratings. They typically hover around the 5% mark most days and yet drew approximately 4 times that amount during the London Olympics. TV One were the biggest losers with their lowest day delivering only a 13.6% share. TV2 also dipped while the impact on TV3 and Four wasn’t as big.
However, the most interesting line in this graph is the Sky one. With exclusive, live coverage of the games, and despite being in about half of all households, there really doesn’t appear to be any impact on their share of viewers at all.
Source: Nielsen Television Audience Measurement, All 5+ Daily Share