tedster - 1:09 am on Oct 3, 2010 (gmt 0)

My understanding is that a browser fires an onload event for every object (including the body), whether or not there is a script running that is listening for that event. In other words, the browser itself always notes the fact that the object is loaded.

The greatest majority of site visitors will be generating information that Google can use - and they're comparing "apples to apples" across site visitors at any rate, so I don't see this as being a source of bad data.