Originally Posted by deepsand

Each DS will still return different results. And, as the average user does not specify the DC to be queried, one cannot rely on that particular DC which is most likely to be queried from ones own machine to be representative of the results seen by the target audience.

For example, as search for 'tomato world,' w/o quotes, shows the thread of that name here at WPW to be in either 5th or 6th place depending on which DC is queried. While, in this example, the difference is small, for those whose goal is to be on a specific page or higher, this 1 place difference could translate into a difference of 1 page.