Extreme Couponing is an entertainment show, nothing more. I enjoy it like I enjoy other TV shows, but I don't aspire to have a room full of stuff I'll never use. A lot of these people seem to have some hoarding/deprivation issues that make them do what they do to such an extreme.
I don't do anything close to extreme couponing, but like others here I do combine sales with coupons on items I use all the time. I have a nice stockpile of health/cosmetic items like shampoo, deodorant, toothpaste, etc, that I no longer buy unless I have a coupon AND the item is on sale. And I usually have three or four coupons for the same item, but that's because my FIL gives me all his coupons (he can't be bothered!), plus DH sometimes finds coupon flyers at work from the newspapers left in the teacher's lounge. We also get flyers at the commissary and in the mail, so it's not unusual for me to have, say, four $2 off coupons for the rather expensive anti-perspirant my DD and I both use in the summertime, and I'll use those coupons when the item goes on sale for $3.99, making it only $1.99 a package. That's a huge savings when its regular price is over $7 at Walmart! DD also likes to use the rather expensive Colgate Optic White toothpaste. I wouldn't buy it normally, but it's often on sale at commissary for $2.25, and I'll have three or four $1 coupons, making it much more reasonable (I usually use Pepsodent myself, I like the flavour better and it's super cheap at the commissary!).
So I save a significant amount if I'm careful and watchful of sales, but I restrict my coupon use to stuff we really will use. I just don't get the point of stocking up on 97 bottles of hot sauce, or a hundred-year supply of mustard, just because it's free or only cost two cents each. I only understand that mentality if it's being donated to the food bank (although most people who need the food bank aren't there for hot sauce!), but you don't see too much of that on the show. It's mostly greedy people who never, ever have enough, even if they have $20,000 worth of stuff stocked in their garage. And it's also occasionally people who use their huge stacks of coupons fraudulently. A couple people have actually been called out on that over the course of the show. That's the sort of thing that helps drive prices up for the rest of us, and may eventually reduce the number of coupons that manufacturers distribute.
Goodness, how I do run on! LOL
"The business of life is the acquisition of memories." --Mr. Carson