"This is to let you know what a difference we have noticed in the dust level of our home since you cleaned our duct work and carpeting.  It's amazing.  I believe if we would have just done one and not the other we would not have seen the results that we have seen.  I'm glad we did both and have recommended to several that they do the same.  We used to have to dust every 5-7 days and now we can go 30-45 days!