Good article.  The problem with most sales organizations is that they manage to an "activity level".  They require their sales reps to have "x" calls per day, "x" appointments per week, "x" proposals per week/mo.  So, the exercise becomes activity instead of results (sales).  In this environment, reps are graded weekly on how much activity they had with usually very little emphasis put on the quality of that activity.  If reps were given the ability to focus their efforts only on opportunities that are REAL and QUALIFIED, you would see the increase in sales that you are actually looking for! 
 
Here is a site that offers other sales tips:  Sales Training Blog
 
Looking for Free Sales Training Tips?  Here is a great site with lot's of great topics for improving your sales:  Free Sales Training Tips