Broadband is a shared resource, so usage limits are needed to ensure everyone gets the service they pay for. Without usage limits, a handful of people with high usage habits could effectively slow down the experience of the other people using that network.
Even with usage limits, customers using data-intensive applications such as peer-to-peer (filesharing) can have a negative impact on the experience of others, even at busy times. For that reason we use the most advanced traffic management in the industry to ensure that everyone gets a fast experience for web surfing and other time-sensitive applications.
This graph shows the traffic through our network over a 24 hour period. You can see that there is a lot of peer-to-peer traffic at night when the network is quieter. If it wasn't for traffic management, this traffic could slow down web surfing during peak times.