&gt; <i>But that isn&#x27;t to say it is all voodoo that doesn&#x27;t work. Its just that to measure it properly you need some very expensive technology and&#x2F;or proper stats training.</i><p>That&#x27;s what I believe too. It does work when done properly, but most of the shops are not equipped to even begin to understand how to do it.<p>What kind of expensive technology do you mean in particular, if I may ask?