Relevancy Score formula for email

Ron B. posted the following formula in Tamara’s http://www.b2bemailmarketing.com/ blog, in the Email Insiders Summit live feed:

Revelance Score =(Unique_Opens/Total_Valid_Recipients)+((Unique_Clicks*3)/Unique_Opens)-(Unsubscribes/Unique_Opens)-((Spam_Complaints*10)/Total_Valid_Recipients)

It’s primarily an open/render based metric, and originally posted on: http://blog.deliverability.com/2008/04/we-need-a-way-o.html