But I digress.... Good luck guys!
Go to Low End Box and browse through hosts. Each one in the comments section will have a 10/100MB test file from one of their servers. As a bonus it will also tell you the geographic location of each server.
On top of all of this many scripts on the page from ad companies are not only tracking the ad but sitting on every event loop. Now when you scroll change focus or many other actions your browser will have to deal with that as well again distracting from the content.
In the end the content creator is losing their power of conveying their message in relation to distraction ad revenue.