There is so many "Tricks" employed by the ISPs that it is hard to account for all of them.
Even within the same ISP in different regions there are differences in Bandwidth control.
Most of users do not even know what exactly is going on because it is Not affecting whatever they use the Internet for.
We have a tendency to think that the very little percentage of people that complain on Enthusiasts' forums are a representation of main stream reality.
Well they are Not.
As an Example were I am at the general Bandwidth is 20 Mb/sec down.
However, at the moment that I download a files that is larger than 100-200MB the download "Speed" starts to go down until it stabilizes on 12 Mb/sec.
Of course none of my friends and neighbors are even aware of it cause they are Not engaged in downloading Huge files.
In my case it means that it takes more time to download ISOs from TechNet or MSDN.
This difference in time is nothing that I lose sleep about, or feel Anger about it. I know that if I professionally need more I can do the right thing and get Business grade service.
